I for one look forward to the challenge. I will start off on the normal difficulty and if I find that I require a greater challenge...then of course I will go harder. If the only challenge at this point is then optimizing the party to control the battlefield in a manner that works for me (including my Inquisitor) then that is also a strategy.
It is possible that given the mix of NPC's a certain Inquisitor race, profession and specialization will be quite key t a victory at the highest levels...as mages tend to be a bit squishy at least at lower levels. Having one big tank in the party with two archers and a mage (assuming one is limited to 4 people) would seem optimum to me. However I could see one archer and 2 mages, but if one ever did 3 warriors and 1 mage there might be trouble. 2 Warriors and 1 melee rogue might be even worse. But all of this will also depend on positioning and which enemy it is you are fighting.
Maybe some battles will get over with quickly with overwhelming melee force and others result in insta-death. Whenever I get to start the campaign I will probably record all of my sessions and post them.