My perfect-world-ideal solution would be to get rid of that level 90 talent, but I'm not sure what would replace it.
As per what I have down in my suggestion, basically Fire Elemental would be the go to for Elemental and Enhancement, where it would have a single target ability, AoE ability, and a utility that could benefit the Shaman.
Earth Elemental would be for Warden (and Resto to a lesser extent). It would have an AoE attack, a taunt, and some sort of utility that could benefit the Shaman.
Obviously they could be interchangeable depending on if you needed more defense (I would assume the EE would have a defensive utility) or need more raid damage (where resto would use FE or something).
I've just never been a big 'pet' person. Nor have I ever really imagined Shaman as a class that fit that role. The closest I would come to a compromise (outside my own suggestion for a 90 talent - which I'm still very iffy on) would be perma-wolves for Enh. But obviously they would have to be redone, and could only happen if PE went away.
Finally, to add to the part you quoted. Shaman are still able to wield all elements. Specifically with Elementals, we're not really 'masters' of them. Rather, we just ask for their aid. So using a FE for Enh isn't really stretching outside of anything. I just like a clearly defined theme within stuff.