u/Wide-Cook3431

Specifically, with Sparx being the Ash of the pair, and Spyro bring the Pikachu of the pair. 

Pre-existing factors: 

Spyro/Pikachu;

Both seen as cuter than Sparx and Ash from a general consensus point of view.

More powerful than Sparx and Ash.

What could work from the Ash/Pikachu dynamic;

In the anime, a reoccurring scenario is Pikachu getting kidnapped by Team Rocket, and Ash going to great lengths to rescue him. This, in my opinion, could also work for Spyro and Sparx; as Spyro tends to be impulsive, not thinking before acting, this could lead to a situation where he falls into some kind of trap, and getting kidnapped by a villain, leaving Sparx to rescue the little dragon. This could happen in games occasionally, but for a reoccurring thing, I think it would be better suited to a hypothetical Spyro comic series or TV show. 

As Spyro doesn't have fins, I felt Sparx holding his cheeks or horns would suffice. Sparx is in Ariel's place because he's (said to be at least) older than Spyro, and protective of the little dragon, like how Ariel is protective of the younger Flounder. Plus, both pairs of characters share a sibling-like dynamic.

I'll be making tweaks to these pics one of these days, such as adding back Spyro's missing horn, and removing Sparx's eyelashes, lol

If they did, Spyro would probably arrive in the Pride Lands via a mysterious new portal that intrigues him, and meets Simba.

I think they'd get up to all sorts of mischief, pranks, and the like, until getting scolded by the adult lions.

Maybe they'll get into squabbles, or perhaps Nala would get jealous, thinking Simba likes him more than her?

But in your opinion, what would happen if Simba abd Spyro met?

Specifically, with Spyro being the Flounder of the pair, and Sparx being the Ariel of the pair.

In my opinion, yeah. Though their personalities wouldn't one-to-one clones of Ariel and Flounder;

Spyro would still be cocky arrogant, confident and outgoing, but will also be insanely loyal to Sparx like how Flounder is insanely loyal to Ariel. Also like Flounder, he could have "butt of the joke" moments like getting stuck in small tight spaces, like Flounder did in the famous sunken ship scene.

Also, Sparx, personality wise, wouldn't be a full on clone of Ariel. His personality would also stay the same as his OG/Pre-Legend of spyro counterpart, but his protective side to Spyro would be pushed more to the forefront. Sparx would also express physical, playful affection towards Spyro, just like Ariel does with Flounder.