I know there is a ton of discussion in your thread, but it's probably better suited here now. If I'm following you, I understand you want to win now, and at the same time, integrate your prospects into your core to have a monster team in a couple years. There can be a balance to do this, but tough to manage like you said, and you're finding out now where the comfort level is.
If you just want to collect the very best prospects, regardless of position or situation, that's fine...but I think you can take it a step further. Think about it, why do you need to hoard 3 SS right now? Very few, or nobody, in your league are taking the approach you are taking. One of them can be dropped IMO. I'd also cut Reyes over DeLeon and Snell for the almost 100% fact nobody in your league is going to pick him up (based on how your league drafted) and we are gaining zero information on him for a few months. If he did get picked up, it's ok as SP prospects come and go. We should find out alot about DeLeon and Snell this year though.
As far as the SS go, IMO Rodgers is the lock to keep around as he has the most fantasy upside. The other two have their merits to stick around, but I'd probably lean towards Arcia as we should see him this year, but Swanson probably gets snagged because of his name. Tough call.
So, this would be my order of cuts if they ever need to be made: Reyes, Swanson, Arcia. But I could easily be convinced to flip the SS. I would not cut Mazara, Moncada, Snell, DeLeon, or Rodgers unless my season depended on it.