I do think that big guys can be pounded by recoil more than smaller guys. I don't think it is purely mental, I believe that physics has much to do with this. A big guy has more mass, thus inertia, and takes more to be moved. So the intial absorbtion of recoil to overcome the larger fellows' inertia is greater.

I don't find shooting a 375 prone to be an issue, maybe here a bigger guys greater mass helps absorb the recoil.

I'm 5'11" and if I'm really, really fit I'll go 215lbs. I'm still really fit at 225lbs.

JPK