That was Amadeus Cho Hulk, also btw... all the Hulkbuster armors suck they always fail i have no idea why they get built other than they look cool sometimes.
I mean you could but even then that's mostly due to his shield which can and has tanked hits from beings that hit harder than Hulk, you don't see Cap using it to slice Hulks arm off.
IIRC isn't it stated that his energy weapons at max setting can cut through steel? Don't see how that is better than adamantium unless i missed something which i could have easily. You still need a hell of a lot more than class 4 strength to cut through Hulk as much as BP did, it kinda goes against the entire history of Hulk and Wolverine.