Board Thread:The Heroes of Olympus/@comment-29729973-20170602033139/@comment-31481772-20170602035054

I would say :

Top tier:  Frank, Reyna, Thalia

Frank, Reyna and Thalia are very skilled with multiple weapons and fighting styles. This could be because of natural talent (Frank, Reyna are children of Mars) or excellent training (Thalia is a Hunter of Artemis).

Second tier: Percy, Jason, Nico, Annabeth

Exceptionally skilled in their favorite weapon, but only their favorite weapon (two weapons for Annabeth).

Third tier: Piper, Hazel

Very skilled in their favorite weapon,  but only their favorite weapon.

Fourth tier: Leo

He is not a natural fighter. He hasn't had enough battle training either. But he is effective in battle because of his fire powers, quick thinking and reflexes.