So far, the HK are the only team of visibly competent antagonists Oda has introduced into the story.
Yeah so far the 3 of them could bully any country in no time while handling themselves fine in 1 vs 1 against anyone bar top tiers
Great crowd control, long range game (the guys could eat while fucking up Elbaf), great mobility (Gunko bird, Sommers vines dragon, Kilin being a horse), can trap people and/or take hostages easily (arrow, sleep, vines) etc
and this is even outside of regen
a great assault team