Don't know, ahaha. Some other things you might consider, though... bumping one of the multipliers (it's either gold or productivity/resources, iirc, though I've forgotten which one) in world gen will also net you more D income from Ermor's capital site (MA ermor, at least), if my memory's not failing me. Also probably run 75% magic sites, and possibly consider something like chocolate sites for extra magic sites and more useful ones... you're going to need a lot of D income to pull it off (or leaning hard on indies, which is a notably inconsistent plan) regardless if you're trying it as MA ermor, since you need the D for both your researchers (which are honestly kinda' crap as researchers -- very expensive in terms of gems for the RP) and the burden itself and investing enough into said burden it doesn't get squished ASAP and more or less everything else you have to do in the interim.
If I had to guess, your optimal path would be picking up some air (or something of similar intent, fire, maybe astral or blood at an extreme stretch -- you're after low construction research boosting items) and then using that to boost your lowest cost researchers (which are also your most gem efficient, iirc)... maybe even dip into enchant as well, to summon revenants to hold research items, if that's cheaper than summoning your native research fodder (which I don't remember if it is, so... yeah). Ideal would be playing a disciple game or trading with another nation for research boosting items and/or death gems, so you can skimp on mage turns and whatnot.
More than that, I couldn't help y'much. Not much for the raw number crunching part of the calculations involved in the question, heh.