I shoot guns that vary from sub-5 lb. .410 doubles to a 9.4 lb. 12 ga. HE Fox, to my big, heavy MX8 P-gun. I can, with some adjustment to my shooting style, shoot them all acceptably. It is impossible for me to shoot the vastly differing weight and MOI guns with the same shooting style. My heavier guns take a more deliberate shooting style. The little featherweights require more of a snap-shooting style, where I begin to track a bird with the muzzles before ever mounting, and during the mount, and then when the butt seats in my shoulder pocket the trigger breaks immediately thereafter.
When I shot a lot of NSCA tournaments I enjoyed the sub-gauge events as well as the Main. But, since I shot them all pre-mounted I would shoot a few practice targets with each different gun prior to shooting for score. This allowed "muscle memory" to happen. If I didn't do that, the first couple stations would be disastrous.
The truism, "Beware the man with one gun." is 100% correct, but with practice, multiple guns can be shot very well, IMO.