Hi,
According to me it could be great use pets abilities when we want it work. One or two primary abilities, not more, bind in our keyboard. Not all abilities, from modding, are available with that I think, but many are. For example MOA's AOE shield that reduce projectile speed and reduce damage of those projectiles. , and more, I don't remember all the abilities, just the one I was thinking first.
Some things maybe should be good in all compagnons, but for me it's better if it's not like this. For energy for example. There is so many source of energy, so put energy recover for all pets is not a good idea. Pet choice must keep for our own reasons and preferences, and situationnal of course (I play Djinn with my bubble Nyx- I play mecha Kubrow when I'm tired having static gameplay with she).
At least I'm sure DE will build something good. They are not out of great ideas.