Mine is very careful of having other players bots in your squad - it's often much more useful to equip you AI with equipment that would boost your main characters damage. As an example, when I got rid of my social squad bots earlier, my damage v burning went from 400 to over a 1000!

Another tip that I'd like confirmation on - grinding incursion missions, from what I can tell, sticking with the world's unfair mission (with the incubators) and grinding those masteries as its the fastest one would be best, THEN going to the other incursions and completing them on the highest available one whenever you want to. Then, with looking for specific tier gear, going to those masteries and so on. Again, please correct me if I'm wrong it's just a theory!