Sure assassination has only four buttons if you want to do suboptimal dps and use none of the rogue utility. Is it a hard spec? No, not really. Sub has significantly more things to manage than mut. Sub is also more frustrating and detrimental to your dps if you get it wrong. Unless you are extremely comfortable as sub, and can consistently play it optimally, mut was doing very similar dps before the 6.2 buffs. Now that mut is in a better place on paper, it feels much better than it did in BRF. Can't wait to get my archi trink and 4 piece.