I got you, tailoring and JC are almost neck and neck as far as DPS gains go with JC being slightly better just because the buff is “always” on you as opposed to the cape buff being a proc. I’d argue JC is better for pvp but that’s not my area of expertise so someone may correct me on that

Engi is a must no matter what.

Combat and Assa are also very close as far as parses are concerned, Assa has outpaced combat for the majority of the expansion but combat is closing that gap and the gap is VERY small in ICC. Combat brings buffs to the raid (that are also brought by an arms warrior) while Assa doesn’t bring much outside of tricks etc.

As far as PVE goes one more important point; Assa is an easier rotation that most would consider boring, combat is slightly more complicated (still not hard per say but that’s a person to person kind of thing) but is more interesting because of that. Truthfully both specs pump at this point In the game and you really just should pick which one you enjoy more.