I get what you are saying Dylan, but the Lavonte David example proves your first point to be somewhat irrelevent.
From what I am hearing, this is not too big of a deal; and like I was saying earlier: we are very well stocked at safety. Our starters this year are a junior and a sophomore. This kid being a juco does not make that big of a difference in our future depth.
lavonte is a pretty unique talent and even he only got to start early because of injuries to our top two linebackers. he's had to learn the system on the fly and this has left him out of position on many occasions. yes, he has made a ton of plays (and probably deserves consideration for league defensive player of the year), but his mental lapses are also a big part of why our run defense has struggled at times.
no matter how talented stafford is, it would be difficult for him to become proficient enough at the defense to step right in with only fall practice under his belt. this is particularly true when we have pretty good returning safeties in osborne and smith (not to mention cooper and jackson waiting in the wings). perhaps he could give cassidy a run at peso.
i truly hope he's awesome and that he is an impact newcomer, i'm just saying that arriving in the fall is not an ideal situation and could easily explain the staff cooling on him (if they actually have), particularly when early eligibility was something he had direct control over.