This is what I do with Shadow:
Dog No.1: wrestling - Unless I am 100% comfortable with the other dog, I supervise the entire wrestling match with the other owner (no one on cell phones, other conversations, etc.). If one dog starts getting a little too into it, we break them apart for a few seconds/minutes and then let them return. I have also taught Shadow "gentle" and "release" and use them often -- even when the other owner says not to worry. I use the wrestling match as training reminders. Shadow often grasps around the neck but thankfully doesn't bite into the skin. He has lots of doggy friends that wait at the gate for him to arrive and start up the match. The dogs like to get attention from me and try to get him jealous -- they will jump up on the bench to cuddle and then slap him when he comes by. I have also taught Shadow "waterbreak" and now most of his opponents also respect the term. As soon as I call out -- they break apart and we all run to the fountain and I fill up the bowls. It seems that Shadow and I have done a pretty decent job together because he will adjust the level of play to the capability of the dog -- other owners tell me that their young puppies love to have "Shadow-time" and learn their moves. Another thing to mention is that we are very cautious about letting more than two dogs wrestle each other at a time and will move the match to a location a distance from the crowd -- it can get overwhelming if the referees (barkers) or herders (heel nippers) join in.
Dog No. 2: Shadow was the humpee from when adopted him at 10 months until he was about 2 y.o. It didn't bother him one bit. He appeared to consider it an invitation to wrestle or start a chase around the park. A couple of times, he would bounce around the park with an obsessed Boston clinging to his hips (hilarious!). Currently, he is the humper -- but, his humping is rarely for dominance. It is to instigate play and interaction. I did work on minimizing the humping by training with a receptive owner and both of us correcting him just before raises his legs. However, if a yellow lab shows up I am out of luck. When a yellow arrives, I apologize in advance to the owner, ask if there are any physical issues...often they say not to worry and that there dog is the same or that their dog will safely correct him (which, IMO is better said in doggy language). But if there is a physical or mood issue, I watch for the glint in his eye and get my "no humps" and "uhuhs" ready.