I used to do a lot of skateboarding so one calf (my left) grew larger due to all the scooting about I did. Since then they've evened up again.
If you take part in a sport that requires asymmetric use of your body you may well find that different muscles develop more on one side than the other.
In your case, I think adding in a bit more work for the smaller calf would be worth a try. On the other hand, you could leave the calf that is larger and only work the smaller one. Once it has caught up, go back to working both. Single-legged calf raises holding a db would be ideal for this. You could also do negs just for the little fella assisting the concentric with your other leg.