I think Romero is a very bad matchup for him, as he's very defensive (mostly), can withstand a lot of damage, has a lot of power and has great wrestling while being (most likely) the most physically strong MW together with Paulo Costa. I think Romero's defense is pretty good as well.
I also think that Kelvin Gastelum has a good shot at beating Anderson Silva, as long as he used his wrestling and doesn't rush in carelessly.
Other fighters that i think can win are Cannonier and Adesanya.
Weidman isn't at MW anymore, otherwise i'd include him as well.