There's no other player I can think right now, which will make me trade one of those three.
If Trout is available, this will be the order in my mind to start trade conversations:
1st Severino, he's great, but there are more pitchers in his level on the league
2nd Judge, it's almost impossible for him to duplicate his rookie season, he might have the shorter career (unless he's moved to DH in a few years)
3rd Sanchez, he plays a premium position, no matter what some people say I believe he will be a plus defender very soon.