The means they were willing to use in Skyrim and thousands of years prior are far different. In Skyrim the Thalmor want to wipe humans off the face of the earth. In ESO they want to stop the younger races from ruining the earth by keeping them from power.
In Skyrim it made sense because the end goal was something pitting humans against each other only helped. In ESO, the entire goal as stated by the lore, the definition of the AD, and quotes by Ayrenn herself; the only purpose, the ACTUAL ONLY PURPOSE of the union was to stop humans form sitting on the throne because of what they did when sitting on the throne.
"When word reached the High Elves of Summerset that the Imperial City had fallen under the control of the human supporters of Molag Bal, the Aldmeri Dominion was formed. The High Elves reached out to the neighboring races of Wood Elves and Khajiit with a plea that their combined forces might prevent the younger races of Tamriel from bringing disaster to the world, as they had so many times in the past" - Main Website
"I have no hatred for the races of Man, but they are young. Like all children, they are driven by emotion. They lack the wisdom that comes with age. I would sooner place an Altmer infant on the Ruby Throne than surrender Tamriel to their capricious whims.
The Altmer, the Bosmer and the Khajiit share the common traits of intelligence, patience and reason. We do not seek riches or plunder. Domination is not our goal, nor is the acclamation of power for its own sake. " - Ayrenn
Really, that is their one and only purpose. they have no side motivation, nothing. Just to keep humans off the throne.
THEY DON'T EVEN WANT TO KILL HUMANS. There is no point to put a human on the throne as a puppet because they have no ulterior political agenda. Literally, their only purpose is to keep humans off. the ONLY one. If they don't do that, there is no point for the AD to even exist.