I think he'd last 2 or 3 rounds with Pacquiao, but if we're talking prime Pacman, I agree he'd blast Pillowfists McGregory out in a round.
The ironic thing here is you shitting on boxing is inadvertently shitting on your hero, but you're too dense to see it.
Conor is essentially a boxer. In his own words "I'm a boxer, I've been boxing most of my life". He is a former amateur boxer that is not good enough to be a top pro, so he chooses to outbox high school wrestlers and manlets in a cage instead.
Your hero is a boxer.