A shotgun shooting a given weight of lead at a given speed will have the same free recoil as any other shotgun of that weight shooting that weight at that speed, regardless of gauge.
The limited testing of 3 buck I've done in the past with the 20 gauge YE here has a spread similar to most 00, just more, smaller holes. Another brand might have beaten it nicely.
In your shoes, I'd try both 2 3/4 and 3" buck in 3 and 2 sizes, and go with the tightest patterns. That's if the kick(Different from free recoil) is tolerable.
I doubt that if ten felons were lined up and shot, half with 2 buck and half with 3, that either would show any significant advantages.