You act as if they are the same. even your recent comment that the Thamor are the children of the dominion proves that. again thats not true read the Rising Threat books, the Thalmor had the high elven armies conquer Valenwood and they recreated the Dominon, not the other way around.
The Great War:
"The Thalmor ambassador upended the cart, spilling over a hundred heads on the floor: every blades agent in Summerset and Valenwood."
Thalmor controls the Dominion