Hawkeye is already a featured character in Clash?

A significant part of why people recommend that is so that newer Players don’t get stuck in the MMR trap you’re in, by Champing one 4* and jumping their Roster Scaling up before they’re really ready for it. Since you’re already there, that’s no longer an issue.

That said, you do still want to get all the 3* Champed, because the Champ Rewards really help develop your 4* Roster, but making a little “detour” for a couple more solid 4* Champs first should help more than it hurts from where you are right now.