This is a great point, Reghar is great as long as you just want to run around really fast but in combat he's not all that stellar. Before I got my iLvl to a decent spot where I could handle larger packs of mobs alone I kept Nobundo as my combat ally since he would allow me to stay healthy.
Myrla is the only one that has a weak performance as a combat ally, all I think I've seen her do is summon her Gryphon and deal some area damage with that.
I'm not sure why you think that just because Reghar has a fun ability (that's what I consider it) that differentiates us from other classes means in needs to be removed. If you pick Reghar you are taking subpar damage for outstanding mobility outside of combat. I bring Reghar along any time I know I'll be running around picking herbs as it's nice for me to not have to dismount, but if I'm going to be doing dailies in Suramar City (ghost wolf is so useless with Masquerade) or dealing with tough bosses I bring Nobundo. In other words, I swap to fit what I'm doing. Which is what I believe the intent is supposed to be, pick what you need for the circumstances.
Maybe you need to look at why you seem to think you always need Reghar...