Rustam is an underrated fighter. He is 22-3 and 8-2 in the UFC, his only losses were a close split decision against Martins and a loss to prime Bendo back in 2014 . I think he would have good chances to beat guys like Alvarez, Gaethje, Pettis, Iaquinta etc. The only reason why this guy is not ranked in top 15 is because the company hasn't given him a ranked opponent since 2014. No matter how good you are, you can't get into the top 10 if the company refuses to give you opponents from top 10, simple as that. Makhachev and Taisumov have the same problems, both are tough and skilled lightweights but UFC keeps putting them against fighters outside of top 15 each and every time.