My Teddy likes to wrestle. When we first brought him home, he wrestled Max roughly and annoyed him. I had never seen 2 dogs play, so I didn't know what to think. Sometimes it did get out of hand and one of them would end up yelping. This is their way of alerting the other one that things have gone too far.
Puppies can play rough, but I think you are doing the right thing stepping in when necessary. I would intervene when there is biting on the back. Teach them "no bite" and things like "settle down."
Start obedience/trick training both of them now. Puppies tend to learn faster than adults. The training will help focus them. Work with them individually and together.
When my boys start wrestling too hard, I redirect their attention to something else. I grab a few pieces of kibble and ask them to do tricks or we play fetch. They happily oblige.
Best wishes.
__________________ Kristin, Max and Teddy  |