Fleet size question
Just a quick question for my novel / Chapter lore
What would you expect a new chapter fleet to be.
I have a chapter that is a completely new.
Founded specifically to guard a new possible ( but unlikely) route through the rift.
They received a system to guard and somewhat govern so they have a new home world and we're half from the indomitus marines and half a new shipment from Cawl.
All dark angels geneseed.
I want to build a fleet for them but realistic in scale and types of ship. There also will be a fleet from battlefleet ghotic ( maybe other not sure) but they won't be under the control of the chapter directly.
There is a derelict of a battleship of some old design orbiting the home world so they most likely will reclaim that one but it's yet unscanned ( separate novel will be about that ship later ) also some advice what type of derelict would you recommend is highly welcomed.
There is a old and abandoned fortress monastery of some kind but absurdly huge. ( Main story is happening here)
All advices are welcomed.