I ride with my husband and sometimes friends will come along. I don't like big groups. 4 is my max. Just for my comfort.
My husband has a bad habit of letting his horse ride up my gelding's butt and I don't want to get in an argument out there about it so I just look back and give him "the look". Today tho he let her bump into the back of him and he stopped and gave a warning. I said, "he's going to kick her!!" I like being behind if people don't keep their horses back at a good distance.
It's hard when riding with other people especially if you're on a single track trail. You always have some go at different speeds. Even mine, if he's behind a slow poke, he will get antsy and will try to push them along and I'm kind of fighting with him to back off. If it gets too much, I'll say.... "when it's safe, I'm going to get in front for a while."