Here's the kicker with .22LR pistols: Since there is not as much recoil, you can get away with a weaker grip, and still be able to sight-track well. You could be tea-cupping it, and still have a nice group quickly. If you do the same with your conventional pistol calibers and that won't fly.
So what it boils down to is: How good your grip is relates to how well you manage recoil, which relates to how well you can track your sights (with the assumption of a perfect trigger press and proper slight alignment.)
From my experience, the two best ways to improve your grip is by grip technique, and grip strength, in that order.