Well, if he isn’t using Ryuo, then yes. Base ACoC > Base Ryuo > G4 Boundman.
Just like G2 and G3 were weaker than Katakuri and G4 was relative, the same applies to Ulti.
Does G2 and G3 have AP equal to ACoC Yamato?
There’s a reason Ulti faced Yamato and BM, while others faced SH