[Discussion needed][WIP] Dangerous special zombies

Fear the special zombies!
This PR buffs the dangerous level of many special zombies (The previous zombies buff PR mostly deal with "normal" zombies)
Now, this may upset the balance a bit (or maybe a lot) so that why any comment is much appreciated. The reason for this buff was to restore the special zombie's difficulty in relation with common zombie before this PR #5822 (after that buff common zombies is just as strong as special ones, minus the flashy abilities).
I mostly buff hp by 10 or more to be higher than the standard zombie. With the following notable exceptions:
Feral hunter: Tougher (60->90 hp), slightly faster (still lower than zombie dog). If zombie dogs are the scout, then feral hunters are the vanguard and flag bearers of the zombie horde (More dangerous now)
Skeletal dog: Give it the [BLEED] and [HARDTOSHOOT] similar to the Skeleton.
Zombie hulk: 480HP. Truly something to be feared. Also to make it more consistence with the description (the size of 6 men..) 6 times more hp than your normal zombie.

Buffing hp only is pretty bland but it's the safest way to not screw thing up too much. Special zombies aren't as common so I'd like every encounters with them to be intense and dangerous, got any suggestions? Should I buff other stats too? Or did I buffed them too much?