Use corso, bowdaar is an aoe tank, he has awesome abilites to grab everything. Alot of people dont realize it but bowdaar isnt squishy he is just tanking everything.
Corso on the other hand is a single target tank. When you use him he is tanking 1-2 things usually and you are spreading the damage around. your first companions dont have heals, but you have a small passive heal with pugnacity.
I put corso on dps not guard, i remove his harpoon ability and i stealth in for the 1st shot, he usually picks up a mob or 2 while i waste the normal mobs. Most of the time we are both above 80%. Pugnacity ticking im usually full health and only have to heal corso once every 3-4 pulls.
If your insistant on using the wookie, you really need to keep his gear up to date. and if u didnt change his entire beginning gear, he is pretty bad its super end heavy.
once you get risha... wow you 2 blow up everything together. the only thing i dont like about her is fighting golds, you end up tanking it completely and spend most of your time keeping yourself up than dpsing, but for regular pulls... its like night and day from having corso.