It isn't irrelevant though. 30% More DPS means, you're able to cleave adds and clear significantly faster so you have less time to make mistakes and have to deal with fewer mechanics. Healer mana is the problem, not the mages' mana. Particularly in preraid gear.
In addition to their lower personal DPS, mages will have to be within Lucifron's curse radius in order to do DPS which means the majority of your raid will be cursed every 15 seconds, requiring your mages to spend at least 3-5 seconds (assuming your macro functions perfectly) out of every 15 decursing.
How you would manage the magic debuff I'm not sure. Alliance would have an easier time with this since you at least get paladins along with priests for dispelling but even so, macroing magic dispels will still be very time consuming without multiple priests in each group, which you won't have. Even with 8 priests, which is still too many, it would take each priest 7.5+ seconds to dispel their entire party. Macros are never 100% effective so you will inevitably see impending doom detonations on each cast which will probably result in deaths.
Again, these are just the issues with one of the simplest bosses in MC. Some of the other encounters are much more micro intensive and require CC, interrupts and movement on several targets all to be microd at the same time while tanking and healing 40 characters. Particularly without /focus, I just don't think this will be possible for a single person to manage. Interrupting or CCing the 4 healers on Majordomo alone would be a challenge to box even if that was your only job.
Something else to consider is the sheer amount of time it would take each week to farm the necessary consumables for 40 characters. I don't think there are enough hours in the day.
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