Actually, I beleive that Tamers in pvp represent the exact opposite of the Darwinism ideology, where only the species who adapt get to survive.
The ruler of the world (owners, devs and other UO staff) want to have a large population (suscribers) that enjoys the game. Now, on the pvp side of the game, there are thoses who suck badly, and would disappear faster than the grand panda, and there are thoses who can adapt, learn to cast faster, learn to target faster, explore the different combos, etc.
Thoses who suck badly, under darwinism rules, should logically disappear, being bored at dying constantly in any situation. But that would leave the ruler of the world with a smaller population (less suscribers) and that would not be good.
So in his great wisdom, the ruler of the world created a helper for the players that sucks badly. A helper with 10 times the hit points, impossible to interrupt, that can cast on you several screens away. All the player who suck badly has to do, is to say all kill and target. Preferably, he will also have triggered a macro to put the player that doesn't suck badly on foot. No need to worrie about the combo or whatever, the helper takes care of that.
The problem with all this is that the players who don't suck badly got tired of getting killed 3 screens away by the helper of the player who sucks badly. So now, the players that don't suck badly and would usually dominate the world have to adapt to the strategy of the players who sucks badly and play a tamer like them, in order to survive.
IMO, that sucks badly