This is the biggest thing right here.
Its important to remember that with these perks, monsters are giving up a LOT of other advantage in combat. Theyre giving up sustained damage youd have with the poison claws, burst damage with the DI perks, overall ability damage without cooldown reduction- Etc.
Against a good team of hunters, it can be difficult with even the “glass cannon” comps to get a down (let alone secure it), WITH these perks.
Let alone without them.
1400 hp- Thats what you get from the tier 3 perk. A couple primary empties and another volley from torvald. . 1 extra thunder strike and a few hits from lennox. Another go of SS from Parnell, etc. And this is just the assault- let alone the medic, support, and trapper- Who will all have easier times doing their jobs because the monsters are kicking out less damage overall. Another cycle or 2 from the hunters and their abilities. If the monster DOESNT get a down in that time frame, hes taking more “extra” damage than these perks will grant (Or more accurately, taking it faster). you as hunters can think of it the opposite- All you need to do is survive a cycle or two of abilities EXTRA from the mosnter- which again will be easier, because its doing less damage.
I wont say that these perks were perfect- But they werent grossly overpowered, either. Again, it was tough to get downs WITH combat oriented buffs. Its that much harder without them.
(Yes I know theres the armor perk as well, but its a similar story. Theyre giving up combat power there as well- and it does make a difference)