I have some suggestions
CEDA: Springtrap because he came back after being trapped in a burning building
Jimmy Gibbs Jr: Roxanne Wolf because she has Roxy Raceway
Mudmen: Nightmarion because it fits with the erie nature of the swamps, or Phantom Mangle because they look like they'd be in a swamp
Clown and Riot I think really fit, and I think that whatever the construction workers are probably fits.

because of how jimmy is so rare he should be golden freddy

Or Shadow Freddy

I used TUMTaRA and found out Jimmy Gibbs is springtrap.

And construction crew are Endo-01

Thanks, Saul

i feel like phantom puppet would work for the swamp