So I main a warlock and have completed the prison of elders up to 34, doing 35 soon but i have school commitments. Everytime I completed each level of the prison was with a titan and a hunter. Honestly I feel like hunters are just as helpful as titans. Being able to go invisable is a great save for revives and working towards the mine objectives.
Every class is equally helpful and useful.
-
I main a hunter and ive had to be set up full invisible a few times because there were a few parts we'd always die, (mainly mines). But sometimes, even if your invisible they still see you sadly.