Nice
I use a massage ball with spikes on it. It's good but will make holes in clothes over time and leaves temporary red spike marks on the skin lol it pins the muscles down really well though
Lacrosse ball will do the trick. I haven't tried rolling the rear delt though. I guess you can lie on the floor? The ball might move around a bit. The side and front ones can easily be done against the inside of a door frame and wall respectively