To avoid "recency bias" I would put Cowser on *both* exceeded and below expectations lists. He massively exceeded expectations for April and has almost (but not quite) as massively underperformed in May. Overall, I guess you could say that he had such a great April that he is still outperforming overall, but arguably that "ignores the trend line". Rather than get into whether the trend line or overall production is the better metric, just put him on both lists and say he has been really good and really bad.
Gunnar is better and was younger last year than Cowser is this year. I’m just saying that the similarities are there between the two. Last year, Gunnar had strikeout issues through June (31% K rate), looked like he was guessing (13 looking K’s through this date in 2023), but hit the ball hard when he did make contact.
Cowser has strikeout issues (31.5% K rate), looks like he is guessing at times (9 looking K’s so far this year), but hits the ball hard when he does make contact. He does whiff a lot more than Gunnar so his K rate is going to be higher, and I’m not expecting him to put up the season that Gunnar did last year, but he can still make some adjustments based off the past few weeks. Like you said, not all prospects hit, but even with a high K rate, Cowser’s batted ball quality and defense should make him an above average league player. Just how much better remains to be seen.