Usually they don't. Something like Horizon Forbidden West credits almost 3500 people even though Guerilla Game has less than 500 employees, most of the rest is absolutely massive bloat from different outsourced teams and Sony departments - like the "Head of Opportunity Markets Business Operations Tim Stokes from Sony Interactive Entertainment Inc.: Global Business Operations" was undoubtedly very important for the development of the game.

As for Baldurs Gate 3, Larian Studios currently has 450 employees in 6 different locations, so they are actually around the same size as Guerilla. I wouldn't be surprised if the credits end up being well above a thousand people (D:OS2 has around 500 credits even though Larian back then had only 130 people).