Well, two points, which I'd be happy to have 'torn apart'.

Firstly, haven't we all known for the longest time that there's something additional done when hate values change largely? Hate resets on mobs don't cause them to immediately change their target, something else must happen. I think we're all familiar with things like Resheph's Tarsal Slam where the hate reset takes place after. This might be a consequence, or it might be a workaround of something else, but either way it's a strong indication that when hate values change heavily for things other than damage, at least, weird mechanics are involved (possibly trigger based?).

The second thing is, as I'm understanding this, if you want the range increased, you are talking about the THF being able to attempt to steal enmity for target player on all mobs within a certain range of the THF, right? We want to 'stay closer to mob yet take more enmity off targets'. I'd see how the 'reduce number of mobs checked' would work. I don't know about others but I actually purposely do use those abilities often to grab hate off a large number of enemies.

It sounds like what is desired should still be possible though. Increase range at which THF can target another player, leave range of 'enemies around THF that are checked for enmity change' the same. This should only matter if the two are related, right? No matter where the load comes from, if the only thing changed is 'distance that target player can be at', there should be no change in load.