Yes, been a probelm for several years on certain mobs...
I remember several years back melee hunting things like allo and ambu would not work well at all since you'd actually be sucked inside of the hit box or behind it somehow, so you'd actually miss since the hit box was behind you sort of. They fixed that on a lot of mobs, but I don't think they fixed it on all of em, and some of that 'fix' that never came is why the mobs affected today still have actual hit box problems...
yes, auto aim and next target, etc. do work most of the time... but
Biggest Issue I've had with next target, last target, auto tool, and loot quick keys (just really started using these quick keys to actually do hunts several months ago - used to always manually drag out bars and manually click before that time - still do the manual thing on taming usually since otherwise you get overkill or auto tool too often after mob is dead or you'll keep auto shooting with auto tool when you really need to 'attempt tame') is that sometimes it is aiming at the wrong point as mentioned above... What I've found is that the 'wrong point' problem is actually worst when the last mob's body is still there on the ground next to you after you've looted it... it's like the system gets confused from time to time over where to put the point between the last mob and the next mob as to where the auto aim is... it's hit and miss as to how often that happens, but it does happen quite a bit. Luckily if you are just using the auto aim thing it'll not actually decay your weapon if the point is in the wrong time - just makes it annoying since there's a delay between time you looted last mob and time you loot next mob....
If it's the 'auto aim' part of the hunting that's the problem you wish to fix, I'm not sure it's really a hit box issue (although the hit box issue is still an issue - just a different aspect of the same situation/issue) - it's more like a mix of rubber banding issue along with the pathfinding algorithm to find the next mob issue...
https://en.wikipedia.org/wiki/Pathfinding
It is all tied together, but I think the pathfinding issue and hit box issue are really two seperate problems - but folks lump em together sometimes since they don't understand that there's two issues, well sort of... kinda confusing to even try to explain... unless maybe you've read some programming manuals on pathfinding algorithms... it does all tie in to the same big problem - Mindark needs to fix bugs and higher skilled programmers that consider all aspects of every bug in game instead of just always adding new 'features' and half ass fixing old problems.
Strangely, there is some bugs related to furniture that I think give me some clue as to what's going on with the auto aim thing... In certain circumstances I think the system's back buffer 'remembers' the last target when it's not there in reality because the buffer isn't getting cleaned out at the right time. Based on the way the gui/hud, etc. work I suspect that a lot of 'systems' in game are all accessing multi-buffers and somehow the system is forgetting exactly which buffer to go after...
https://en.wikipedia.org/wiki/Multiple_buffering
The true 'hitbox' issue is really a pivot point issue.
The pathfinding problem is more of an algorithm bug type issue...
It is all sort of tied together, but really different aspect of the same problem.