Susan, first - welcome to WikiTree!
The traditional way of thinking about "my tree" and "your tree" doesn't have any meaning here - there is only one tree and it is ours - yours, mine, and all of humankind's. The premise is that everyone is related if only we can trace our ancestors back far enough. You can, of course, talk about "my branch" of "our tree", but keep in mind that it is only the piece that you have entered and that it will connect to other branches and to the rest of the tree at some point.
As to your question about making other managers unhappy if you connect more family members to a profile they manage ... personally, I experience a very big thrill when that happens - it's another connection for me and the opportunity to find more relatives that I don't yet know about. I believe most members have the same feeling ... of course, I can't speak for all members, but if it makes another manager unhappy that is their problem, not yours. Managers are not controllers - they are merely caretakers of profiles and the farther back in time, the more members there will be who share an ancestor, so they have equal rights and interests in overseeing their ancestor's profile ... and, as a full fledged member, that now includes you!