I'd like to run with the idea of using "pets"and expand upon it, based on a few observations of wolves and dogs.
I've seen a study on TV where a piece of meat was placed in an inaccessible location, under the metal-mesh crate.
The (tame/socialized) wolf tried to get it, persistently, without success.
The dog noted the situation and asked his human to take care of it. The dog put no wasted effort into digging or biting the metal, but clearly got the man's attention, and alternated eye contact between the man and the goal, to communicate that he was wanted at that location.
At home, I recall a new puppy decided to purposfully toss his ball under a hutch where he couldn't reach it, to make Dad go down on the floor and get it for him. Which was the real goal: go get Dad's head down to floor level.
Dogs have evolved to rely on humans to get their goals met, and even as infants will instinctively manipulate and exploit the known behavior of other lifeforms in their environment.
It's thought that wolves domesticated themselves, finding a niche among primitive humans.
Well, what if wolves (as in your plot) found other species that had resources they could exploit, but happened to not be intelligent? Some other animal that had a social nature and produced communal garbage piles and were omnivorous. Eventually the wolves cooperated in hunting and gathering, and formed combined packs which were more capable than either alone.
The wolves quickly evolved to make use of the other animals as tools, instictively understanding that they do things we can't, and can be used on purpose. Which is exactly what wolves did in real life.
The other creatures, weasles or squirrels or whatever, quickly evolved to rely on the wolves to fill certain roles, including making decisions. That is, what wolves did to men in this department, the weasles did to the smart wolves. So thus coukd really happen: they adapt as it's advantageous to let the intelligent leader (of a different species) make tactical decisions and engage in planning.
Perhaps other animals join the mixed pack over time. Or, now on the road to civilization, the wolves domesticate other species.
The real question is how well can the wolves control the "hands" of the symbiotes? If it's just high-level management of instictive or trained tasks (like how a human directs a canine sheapard), it would be hard to made unique detailed motions.