I think somehow you're overvaluing Crit. If damage you do (damage - target armor is 100, then 1 damage is the same as 1% Crit for long term damage output, if it equals 200, then 1% Crit is twice as good, etc.). MM loses some Crit, but the damage increase more than makes up or it, and for clearing maps, as I said above, damage winds up being more efficient anyway since less of your output is wasted in overkill.