I have both the OP Snubby and the V3 SAR kit bags. I'm an average size guy, usually wear an M t-shirt; 40" chest. The Snubby is noticeably smaller, which I like for running, but the V3 or its parent the V2 hold a lot more. I think on the HPG website they say the OP Snubby has the same volume as the Recon or Runner's kit bag.
A G43 is going to disappear in a V2 Original Pattern bag, so in that sense the Snubby bag will be more appropriately sized. But if you want to carry more than just the basics, you need that larger bag, and because you're a bigger guy, it's going to feel smaller. The V3 SAR is definitely bigger on me, but is so comfortable I forget it's there. If you want to carry more and/or a larger pistol at same point, get the bigger bag. If you value sleek minimalism, the Snubby is better.