Hear me out: Helminth companions.

[Klokwerkaos]

Ever notice how when you have all options smeeta is the only realistic option in 99% oF scenarios?

What iF you could subsume a companion and it would allow the unique abilities to be slotted onto other pets For additional utility.

This does not replace the unique attributes of the companion in question, it's in addition to, this is because without that there is no added diversity, all you are doing is reskinning and trading base attributes.

Want to Farm steel path but your smeeta keeps dying?

Get a pharoh dog and slap charm on by subsuming a smeeta and equip charm on your pharoh.

Want to use dethcube but can't slot gladiator mods because you can't run deconstructor?  Subsume that helios!

How about infinite regens on any of your other sentinels from djinn?

We already know the infestation can now affect both kavats and robotics, so the lore supports the concept.

What this does is it allows more build diversity much like the helminth system does for warframes so that you aren't shoehorned in to one pet.

Note this would only transfer specific unique things to the companion to another companion of similar type (ie pet to pet, sentinel to sentinel).

For example, you could slot charm if you subsume a smeeta, but you could not add kavat mods (mods tagged to only all kavats) to a kubrow.

Much like the helminth system this now allows you to mix and match depending on the scenario, for example: 
having a load out with harrow and adding pillage on his 1 might be a great idea, until you need to clear a demolist, so on a separate load out and config for disruption you might replace his 4 instead or slot a different ability.

The basic concept is simply that you can now have more choice in how you use your pets and you're not resigned to running smeeta, or iF you think it's worth (I don't) running helios with gladiator mods).

All this really does is open up pets as a system, and also give sheldon a reason to make pets 2.0 a real thing that happens one day.