I'll admit, if the "combos" are literally going to be "1-2-3" combos as most of them currently are, then I'd say they should be condensed just like in PvP.

However, I wouldn't mind seeing them do something more akin to the old (ARR) Monk combos. You GENERALLY used "1-2-3" then "4-5-6", however if you were REALLY skilled, there would be times you might deviate, because each part of the combo had a specific EFFECT.

So there might be times you hit 4-2-3 or 1-5-3, or any combination. You could totally get by just doing the two standard combos, but it gave the high-skill players a means to differentiate themselves.

Meanwhile, my DRK pretty much just spams a basic single-target combo, or occasionally an AoE combo. I'd happily condense those into just two buttons.