For fun, I chose a Shadowblade and a Rogue and later on we started playing coop with those.
It is very well possible to deal with enemies that way too, though it is a bit hard as both classes are "similar", but I have to admit that it makes it somewhat... hilarious and fun! One usually needs a contrast to the other class, e.g. melee and ranged, healer and tank, etc., as that makes things balanced.