To be honest I never considered Melendez to be a top 5 guy. I always thought of him as Strikeforce's version of Clay Guida. Thomson beat him up good (and won the fight) and Thomson has never beaten a top 10 guy in his whole career. Neither has Gilbert (I'm not counting the Aoki fight because in fights stuff usually happens). I guess that makes them both top 20ish.
Rookie Hammer Squad 2015
Frankie Edgar - Dominick Cruz - Jorge Masvidal - Cat Zingano - Holly Holm