I think adding war beasts would make Cyrodiil more fun and competitive. Each alliance would have 3 war beasts native to the alliance.
Ebonheart Pact: Mammoths, Giants, Netches, Wamasu
Aldmeri Dominion: Pegasus, Senche-Tigers, Striding Lizards, Lions
Daggerfall Covenant: Harpies, Wasps, Jackals, Duneracers