I agree that established stars/legends are always a risk to compare young players to, though at the same time it's natural to make analogies and comparisons when getting situated with a player.
I also think it's important to stress that the book on a player is not at all written by a partial season of ABs. I'll just say it again even though I'm sure almost no one wants to hear it from me: Cruz should have been in MLB in May at the latest, having these same kind of struggles. There's a fairly traditional path for young players that they get called up, show a flash or two, and then have to go back and work on a few things while re-establishing their confidence. Because of how the Pirates handled Cruz this year, they didn't set it up so that he could fail in MLB and then go back to AAA for a bit (which also probably buys the team what they wanted, i.e. not super two eligible) with enough time in the MLB season.
Just as a quick comparison, you can see that the Phillies called on Bryson Stott, who had bad contact issues at first, then went back down, and since coming back has really cleaned that up.
Regardless, it hasn't been too uncommon for the advance in level to slow a player down, and this has been true for Cruz at the big steps of the way. I remember his early games in Altoona, and I think you can see from his recent interview comments that part of the issue has been in terms of mental preparation and what he's looking to do up there. Specifically, he mentioned how he was almost being too selective about which pitches he can really damage, instead of refining an approach that lets him be in an advantageous position to do the most amount of damage he's going to be able to do vs. that pitcher.
In other words, even when MLB pitchers know they need to execute a pitch, the quality of that for many is way higher than your standard AAA pitcher (obviously...).
We'll see if he can put together a 2-3 week period where the Ks are more under control. I think I said this immediately last night, but if he does that, the quality of his contact is going to mean that he'll hit a ton of HRs in a short period of time. He's got 11 HR right now and it practically feels like a copout to say that 20 is in play if he's looking good for a period of time. He needs a big stretch where it's just 1 K/game with occasionally 2 or 0, and never 3-4 or only once. He's moving in a good direction lately, and even a lot of the Ks he's had over the past week or so haven't been bad ones. Last night he was on Williams late in the game and we needed instant offense. He almost provided it, and a great pitcher just happened to beat him.
Aside from this, I am interested to see how we deploy Castro going forward. He's completely tearing the cover off the baseball since his promotion, such that if it continues, it probably puts a little bit of pressure on Marcano and then eventually Swaggerty and Bae for playing time, assuming Marcano is bumped to the OF more often. Castro needs to keep playing almost every day, and I think once the calendar turns to September and those guys are up here (hopefully), you should deploy 2 of them in the OF with Reynolds for the most part.
Anyways, it's all TBD, but Castro re-emerging as a viable rotation player who is locked in at the plate could be a very important development for how to approach the winter. If he starts edging himself into the starting 2B job, then I think you explore moving Newman or maybe likely, Bae. I doubt Newman gets much of anything, but if you wanted to keep him around as depth, maybe you can use Bae as someone to try and trade in order to upgrade somewhere else. Too many moving parts, but if you have Cruz+Castro as a starting point with Newman and Marcano as bench/utility options, and Castillo as depth with at least some possibility of Gonzales and/or Peguero on the horizon (and the 40-man) next year, not to mention a possible popup player in Andres Alvarez, it's a crowded situation.
For that reason, I think we need a healthy dose of Bae and Swaggerty starting in a couple of days. Whether or not either can be penciled in for a spot is something we should already be figuring out.