Overkill Guardian Rank Perk

Perk description is “Excess damage from a kill is added to your next shot”, but damage goes up x3-5 times, depends on mayhem multipliers. Is it working as intended? Seems like not, it makes sniping as Fl4k feel shallow and cheesy, one universal perk doing more than most of his skills. You can even one shot kill Anointed and badasses with 3 health bars.
I don’t like the idea of universal perks being so powerful, but at the same time Fl4k kinda needs it on Mayhem 3 for sniping playstyle, because of the absurd amount of badasses and anointed, so I don’t know how to feel about it. Right now it feels like lazy band aid fix for Fl4k, while Amara can snipe crowds without it.