Dont think a game like TESO can be a rival for ARR since action mmorpg have been failing alot, one big example is Tera the game started has a P2P title and its now a F2P game, players dont really enjoy much action mmorpgs becouse the game gets boring you can almost fight mobs without getting hit, for me i prefer to get my ass kicked a bunch of times and see that i receive dmg from the mobs then dodging them and do the hit and run thing aka Kite.
