Since 4/20, Arroyo has a 249 wRC+, that's totally going to continue. Even with his recent uptick, he has a 71 wRC+ for the season. He'll maybe crawl back towards 100 over the course of the season, but he's not going to be as hot as he currently is for very long.
Wong is very hot right now, but his overall numbers have been fairly strong for a while. I have more faith in his bat long term than Arroyo's.
McGuire can't control the running game the way Wong does (pop time and strong arm that I mentioned yesterday), but they may go back to more of a platoon once his hand is feeling better again.
Casas is going to need a long adjustment period. He seems to struggle between a patient approach and a passive approach. I don't know if he's being overly selective and is working the count just to work the count or is waiting for a particular pitch. Either way, he needs to learn to make better contact in the zone. It's not really happening right now. One or two games could jump start him, but we'll see. He has the fundamentals at least.
Duran is an unknown. Scouts liked him last season. He was making loud contact in WOO. His new stance is working and he seems much more confident. If his defense is just passable, he should at least be a 4th OFer going forward.
Valdez is a good platoon hitter with a terrible glove. 2B/LF/DH profile if you're going to punt on IF defense. People have said "Valdez should just be happy to be in MLB because he was so bad this season in WOO" but that's because of his split against LHP (306 OPS). His MLB OPS against LHP is 000.