Thanks for the comment.

Yes, I've actually compared damage on the final boss in Fractal Continuum; as best I can determine, there's a small but significant advantage to machinists. Yes, we ignore the adds when the boss is below 10-12%. No, casters usually -- usually -- cannot LB at 20% + and get to within the kill-margin.

I've talked to several casters. The idea seems to be that if there are no melee in the group, caster AoE will have to suffice. I'm saying there's good alternative.