You play on official? Not sure if I could stand that given my building urges... I just dabbled on official to compare it to the latency on my own server.
Bearers do less damage than fighters though (didn't use to, but they got the nerfbat to the face once word about that got out), not sure whether their armour values got reduced, if they were then that extra HP might not count for as much (and even a naked NPC has some armour as that's what the multipliers work with). Generally speaking Thralls are the answer to every problem, if you can get them to actually fight as the AI is derpy as all hell. Haven't bothered with pets (got one from the cave my base is pretty much on top of), but they generally don't have a lot of armour and judging from what I've seen their AI is generally even worse than Thrall AI, so a Thrall with decent equipment will always outperform them (ofc, they're probably great early game, before you get access to all the good stuff), especially against armoured targets, I would imagine (so most humanoids).
Might go back and see how a Thrall fares against the Arena Champion. Fwiw, I was using a T3 Sepermeru (Relic Hunter) Thrall in full Silent Legion with the Doom hammer (and then the Worldbreaker, once that dropped). The Named minibosses that can be enthralled are considered T4 Thralls btw and, if not counting Purge thralls, they have the best stats for their faction (crafters craft faster, use less resources, and often get special recipes. Eg. white/black dye for Purge Alchemist)
Still, kinda proud of myself that I cleared most everything (until this dungeon), without using Thralls (eh, I did skip the dagger boss in the Dagon dungeon, that guy was just ridiculous). Wouldn't recommend it though and I might go back and see how much pain I could've saved myself by using a Thrall