Hawkeye, before his death, was only a master archer. His growing abilities stemmed from Pym particles, so he needed a specific canister to grow or shrink. He became Goliath during a specific event when you needed to be a "super human" to get in. I forget the exact details, but he gave it up pretty quickly.
I've seen Hawkeye do some impressive stuff, his mastery of aim extends to beyond just a bow and arrow, in his solo series we saw him do some cool stuff, throwing a stapler across a room and into someone's mouth, I think he threw a deck of cards and they all landed together. In the EMH mini-series he sinks an entire suit of balls on a billiards table in one shot, etc. He's an unrealized mathematical genius when it comes to calculating stuff of that ilk.
However Cap's a super soldier, and with that shield (with which he's displayed just as many impressive feats as Hawkeye has with his arrows and stuff) he can do anything. Cap takes it probably 7 out of 10.