If Ulfric taught the Thu'um to one man, and that man in turn became a dedicated teacher of the Thu'um to a class of Nords (basically, the reinstitution of the College of the Voice), not only would the Nords regain their heritage and birthright, but they would also turn the Thalmor's greatest ally, time, into their greatest enemy. The more time that the Thalmor spend plotting and biding their time, the more Nords that become schooled in the Thu'um, and therefore the less chance that the Aldmeri Dominion have at defeating a Nord army in combat. Throughout Nirn's history, a Thu'um using Nord army has proven to be easily one of the most powerful military forces that Tamriel has ever seen. Even without the Thu'um, the Nords are one of the most powerful military forces in Tamriel.
As for the Empire side of things, if they won, i'd prefer to see Balgruuf the Greater as High King, he's the most reasonable of their Jarls. Elisif is not a ruler, she'd merely be a "Yes-Man" puppet for the Empire. Maven Blackbriar is corrupt, and not only has ties with the Thieves Guild and Dark Brotherhood, but also with the Thalmor.