I had babies fatter then that. They look fine to me. I would not try to reduce that unless they get SO fat they can't move at all, but I don't see that happening with their size atm. They just look like well fed kits to me.Boy are they taking advantage of the milk buffet
One thing I thought I would mention, is if you notice the very full bellies is significantly affecting their mobility, you may need to find a way to slightly reduce feedings. You just don't want them having overly full bellies to affect their leg and mobility development and risk possible splay leg issues. This would really only be the case if they are consistently having extremely overfull bellies and it's causing them to struggle moving around as they get bigger, especially at 10-14 days when their eyes open and they should start walking around and trying to get out of the nest.