Sacrosanct
Legend
I don't think it's so strange when it's limited to the archetype where it fits theme. I have always been a proponent for speed of play (one reason I avoided WoTC editions until 5e), so I am all for just skipping the process if 99% of the time you know the result anyway. It also gives the fighter something extra others don't get.This idea that you must take out the mooks in 1 hit is just a really strange hill to die on to me.
There are a couple of ways I've seen it done and I've done it myself that is simple:
From Bugbears&Borderlands:
Cannon Fodder (2nd level): If you hit a creature of CR 1/4 or less, its HP are brought to zero regardless of damage. At 6th level, the CR of creatures is increased to CR 1/2, and at 10th level the CR is increased to 1. If the hit is a critical hit, the CR is doubled for that attack.
From GEAS:
Hold the Line (low level trait): You can make one opportunity attack for each creature triggering it this round by spending 3 vigor. This does not count as using your response.
Cannon Fodder (higher level trait). Any opponent you hit with an attack that has a MC of 1H or less is brought to zero vitality, regardless of damage. Attacks against these creatures have the Action Point cost reduced to 1.