Mostly seen this only on server browser. Running into groups of high level players all playing rhino. Isn't always impossible to play against (as long as your team is competent) but having to deal with it is pretty annoying. A lot of times they lock down the objective turning a game of stopwatch into a team death match. This causes a problem as neither team are really receiving any objective exp and only combat exp. for those of us grinding stopwatch matches for cheer, this only wastes our time.
(This is just my own personal experience with this that I've had over the course of the winter event. It's not very often, but it's often enough to cause a little concern)