Grogmar Ghrobash
'Tis better to be alone, then of bad company.
It wouldn't even be a battle, the current Empire would get slaughtered so fast it wouldn't even be funny. The only people who can beat the Aldmeri would be Hammerfell. But if the empire is reunited again, they might be able to defeat them.
Hammerfell never defeated the Dominion. They fought until a treaty was signed. They were also fighting a weakened Dominion force. So I highly doubt Hammerfell is the only people who can defeat them.