Hi! I only just saw your post so it is a bit of a late reply! I can only speak of our own experience but when I see the benefits of swimming on my son Dylan, I think any kind of swimming is good! Any sort of playing in the water works the muscles gently and our physio told us that it did not matter if he could not swim properly yet because any movement in the water was excellent. Dylan is 6 and half years, still struggling with the breast stroke (he's getting there!) but will do just about anything else in the water, including swimming on his back and kicking his legs, and swimming under water. He's still very strong, still getting better (he's a little unusual :)) and always seems to have more energy after a swim. I don't! Wyatt is still young so I would say keep enjoying the water, that's a great thing to have. By the way he's absolutely gorgeous!