Samurai Jack - ONE PUUUUNCH!!!

I'd say that's fair. While they are probably the greatest threat Jack's faced in 50 years, since at least the Minions of Set or the Ultrabots, when their numerical advantage is negated we've seen Jack consistently dismantle them.

On top of this, when they first attacked Jack he was in a bad place mentally and probably exhausted from nightmare-induced lack of sleep.

After Jack underwent some advanced doggo-snuggle relaxation medical care, he was much more collected and prepared, allowing him to trounce these assassins.

Showing that in the end Jack is his own worst enemy.

They change from being ultimate killing machine to "I will attack your fist with my chin"