I dont think you will have much trouble, just spend some time now and then working on setting up macros and keybinds in a way that suits you.

I started with a mixed group (pal/priest/shm/2x mage) and although I cant box them as effectively as if they were controlled by single players I dont really feel that they are too complex to control.

I dont know the classes that well, but I think you have a good team there, each char should be able to take a few hits, so you will have a bit of a buffer of time to sort out any situation that is starting to go bad (my mages and priest have a bad habit of folding very quickly if the paladin lose aggro).