No, Bobby Z couldn't be the driver of Doom's Day nor Jim Jack because:
1. Reptoid is gone, and Jim Jack doesn't compete in Monster Jam anymore.
2. Bobby Z doesn't compete anymore, either.
Since Doom's Day debuted in Tampa last year, many fans have been guessing that Dennis Anderson drives it. It's obviously not him because he competed in another event. If anything, I'm going for Kreg Christensen.
Also, I'm going for this drivers for Vegas:
Dennis Anderson
Charlie Pauken
Neil Elliot
Kreg Christensen
Lee O' Donnell
Morgan Kane