what's the best way to bind an animated java model to a mob?

My current method is in a summoning function, it summons an invisible mob and an instance of my AJ model at that invisible mob's position. Then in a ticking function, I teleport the model to the closest invisible mob constantly. (@e[tag=<>,sort=nearest,limit=1) And to remove the model when the mob dies, i run the remove this function on the model when it's >1 block away from the invisible mob. This has a lot of problems: 1. It really only looks okay on flying mobs, if the invisible mob is walking and looking down, the whole model tilts, not just the head 2. It doesn't get rid of the model when there's 2 of the custom mob, it'll just teleport the model to the nearest invisible mob because of the order of comands (and switching the order just causes the model to not spawn at all)