Uchiyama is an easier fight for Lomachenko than Vargas. Vargas from what I've seen would be a very tough matchup for Lomachenko. Definitely a Loma UD but Loma is getting beaten up in the process.
Loma is staying at 126, Unify & conquer...Why set him for defeat by moving him up out of his perfect division that he has yet to clean atsch