Whilst knockout's anger towards silas is justified. he shoudn't only be angry at silas cause airachnid is the one who killed breakdown and it is quite apparent.

when breakdown died in ep7 of season 2 and dreadwing came back to the warship and knockout saw that breakdown didn't, he should logically piece two and two together and know that airachnid is the one that killed breakdown given that she too defected from the Cons after the incident.

plus in ep 12 of seaosn 12 it is made clear that he is fully aware that breakdown is dead.

plus he even later mentions to Starscream in seaosn 3 ep 8 that she locked up tight on our warship. given he knows this fact he should know the she is an enemy of the cons and that she is locked up on the warship inside the stasis pod for a reason.

TLDR: he should have known that airachnid is. the one who killed breakdown given that she dissapeared from the nemesis and the cons on the same day breakdown died

Now I know many people will say Starscream, but for me it's airachnid cause unlike Starscream, who can be beaten into submission and is, for the most part, a coward, Airachnid is the one con megatron can never trust.

For one, she is much more cold-blooded and bloodthirsty than Starscream, and Megatron knows it cause deep down, dare I say she even scares him in a way, that she has literally zero moral sense. She doesn't have any loyalty to the cause; she kills simply for the sake of it, and the only reason she joined the Decepticons is that it allowed her to hurt and kill whomever she pleases. In other words, she is a true sociopath, with little to no regard for others, and only has the most basic emotions. Even when she was betraying megatron is was more of a rational decision rather than an emotional one. making her unpredictable.

Another reason is that I doubt megatron could easily kill her, given her control of insectiocns and all of her other abilities. he can beat Starscream into submission, but for Airachnid, by his own admission, he said she can be a handful, especially when cornered, that he even sent both Dreadwing and Breakdown to kill her with one of them dying in the process.

lastly she can't be beaten into sumbission continously by megatron just like how he does to starscream. Yes, Soundwave did beat the piss out of her, but only to ensure that she doesn't abandon Meg. even after megatron with optimus aboard the nemesis, he still behaves cordial with airachnid even after knowing what she was about to do(soundwave must have told him immediatley upon his return).

TLDR: She is a true sociopath, cold blooded murder and can't be beaten into submission like starscream in the long run and is unpredictable.

Megatron regarding breakdown

Megatron questioning dreadwing regarding breakdown's remains

Even though megatron rarely shows it, he does care about named decepticons. as of this point in the show, when breakdown died and dreadwing was unable to find his remains, megatron seems pissed sort of.

this shows that megatron did care about breakdown in this context more than his use as a tool and wanted to bury him properly as he deserved. he might have wanted to honor breakdown's memory as a fallen hero. he may act tough and ruthless but when an actually loyal named deceticon dies, he cares and feels sad just like optimus does but doesn't show it as much.

calls breakdown's loss unfortunate

he even calls the loss of breakdown unfortunate.

Megatron regarding silas and why he hated him

megatron meets silas and is absolutely disgusted by him.

when silas meets megatron for the first time, megatron is absolutely disgusted, not because it is a vehicon who was butchered( he doesn't care about them individual as he is seen on numerous occassions threathening them with death, threw one of the warship(lol) and even let zombie cliffjumper kill one of them) , but because silas butchered breakdown, one of his finer warrior and a named con.

he personally felt disgusted and mortified by what silas has done to breakdown for two reasons. one desecrating the corpse of a named decepticon and living inside it's flesh and piloting the corpse is an insult to all of them and the cause. it's basically silas showing of to them like i cut open your friends corpose and wearing his body as a mechsuit accept me. that would piss anyone off and given that they are a millitary faction there would have been strong commradre.

Megatron relationship with named decepticons. he cares for other named decepticons apart from soundwave( example knockout and dreadwing )

whilst megatron is a more strict leader than optimus he isn't a monster to his subordinates compared to let's say muzan from demon slayer( who punished akaza even though he killed a hashira, sladered up6's deaths and killed all the lower moons).

knockout casually boasting to megatron

for instance here knockout is casually boasting to megatron, that oh look i got this boss, but megatron simply scolds him for being a douche. that isn't to bad.

megatron scolds knockout for being overconfident.

gives knockout an insections

he even later on gives him an insection showing that he doesn't want the mission to fail as well as not have knockout killed. whislt you could argue that he did it more for the mission sake but not for knockout personally there are more arguments that shows he cares for named decepticons.

Later when knockout fails to retrive the phase shifter he doesn't scold or punish him, he simply asks him to examine laserbeak and do his job and dispose of the grenande.

megatron knows knockout goes on racing excursions.

megatron even knows that knockout goes on racing excursion abd based on the dialogue even permits it but makes sure that knockout knows the difference between a racing excusion and a mission. so in a way he wants to keep named cons happy and in sound mental health.

knockout casually complains to megatron.

when hardshell scratches knockout he complains to megatron casually saying look at these foul beasts they scratched me, megatron here just retorts it's just a scratch get over it. once again he doesn't yell or berate knockout he simply tells him bro it's just a sratch ( optimus would have done the same if he were in the same place although to a lesser extent).

megatron and knockout talk about OP and securuty

hell even when knockout question him to beef up security megatron gives a calm explanation to put his mind at ease saying that no doing so would make orion nervous but he also made sure that his workstation is next to the storage vault for good measure.

megatorn sarcastically telling knockout he is shocked he would risk his finish given the accident

hell he even knows about how much knockout cares for his finish and his comfortable enough to have casualt conversation with him.

megatorn complements knockout

he complented knockout to make him feel good about himself.

Megatron allows dreading to avenge his twin

Megatorn even tolerated dreadwing outright defying his order to try and kill optimus in memory of skywyake. so he does care about his feelings somewhat atleast. later one when dreadwing even returns having failed so to kill optimus he comforts hims saying that you were lucky. earlier in the episode he even assures him that the autobots will pay for their crimes although when he sees fit.

megatorn adressing dreadwings difficulty in accepting starscream and his sadness regarding the loss of skyquake.

megatron even goes out of his way to search for dreading to comfort him regarding the loss of skyquake under screams command and even wants them to be peace.

Megatron betrays silas

Megatron is telling Silas that he earned the right to be a lab rat.

megatron here betrays silas and tells him he earned the right to be a lab rat for knockout. personally i think he did this because as stated earlier he has a good relationship with knockout and didn't want to ruin that. he cared for knockouts emotional wellbeing and allowing him to torture silas for what he did. also to keep his genuine loyalty. he didn't want to make his medic sad.

but also because he respected breakdown and silas using his corpose as a weapon desecrated breakdowns memory and sadned megatorn cause deep down i think when he heard when breakdown died he wanted to bury him with the full honor he deserved. I think megatron wanted revenge just as much as knockout not because silas insulted the decepticons, but because he as a human desecrated someone megatron considered a comrade and dare i say to a lesser extent a true brother in arms.

TLDR: I think megatorn betraying silas was done more on an emotional basis rather than a rational one as he was quite sad with what he did to breakdown and wanted to avenge his memory and honor just as much as knockout.

Please don't say that megatron will anyway turn him into a lab rat. try to come up with a different way of how this would go.