Smn needs a command to make it's avatar follow someone else in the party or at least a smn version of stay. With avatars favour there are times when you don't want your avatar to be attacking a monster(tp feed or because it has a special ability that makes it absorb physical damage), but at the same time
Due to the small range of avatars favour aura you want your avatar to stay in close combat to give the effect to the party.

And have you ever been in a situation where you'll have your avatar attack something then want your avatar to pull it back and it starts casting an AoE nuke? You try to run away only to have your avatar chase after you with a huge impending explosion about to hit it...

as a smn you do not want to be standing close to the monster yourself due to AoE damage or have your avatar following you with an AoE attack aimed on it. In these situations a follow command would be helpful so your avatar could follow someone else who is staying close to the monster to keep favour in the right place and a stay command would be helpful to stop your avatar attempting to take you down with it.