Warning this is a long post hope its helpful.
1 we don't over sign, not by the actual standards. By made up big 10 standards any team not in the big10 (even though they do it too) over signs by signing 25 players a year. NCAA scholarship rules for football state that each d1 team is allowed 85 overall players on scholly at a time, and a team may only bring in 25 scholarship players a year. By sec rules a school may only SIGN 25 per academic year.
Doing the math if you bring in 25 players a year for 4 years you have 100 players on scholarship. 15 more than allowed. Which means some people on campus are either losing their scholarships or you're cheating outright. Some refer to this as oversigning because you are signing more players in a class than you have spots for. However, since no one outside of the university and team knows who IS and IS NOT still on scholarship at any given time it's ridiculous to try and guess and make a deal of it as well as the threads that pop up of "how do we get to 25 (85)" on the recruiting board. Players lose scholarships all the time for disciplinary or other purposes and we never find out, that info is protected and honestly it's nobodies business. No matter what a school or coach says scholarships,to any school, are not guaranteed, and can be revoked for specific reasons.
It's beyond us to know it's not public info and is anyone who offers info is just speculating on rumors. The easy answer is that nick Saban is smart and can count to both 25 and 85 and leave it at that. Don't bother explaining it to anyone on a message board just go back to lurking or don't engage them. The big 10 hasn't sniffed a title since wifi was a household product, they need something to crow about and that's the only thing they got.
2 when sec fans discuss oversigning it's usually in regards to signing more than 25 players in a class. Sometimes teams can back count because they have open spots from players leaving or nor qualifying in the previous class and can back count them in the previous academic year if they enroll in January. However before the hard cap was in place it was not uncommon to see teams sign 28-30 players with some being placed in JUCO or prep schools due to academic or clearinghouse issues. Houston nutt signed somewhere around 35 players in his first ole miss class. That was the beginning of the "Houston nutt rule" creating a hard singing cap that now stands at 25, back counters excluded.
This was very common in the sec but now is more rare, though I'm not certain how ut has found room to back count the entire state of Tennessee in its current class, but that's not for me to ever figure out. It's a case for the NCAA and if ut makes it work good in them. Oversigning is not a reason a team becomes good or wins, good recruiting, player development, coaching and discipline of the players makes that happen regardless who you sign and who's on scholarship, as well as a lot of luck when it's needed. As we saw this year talent alone doesn't get it done.
Sorry for for the length of this message, but i feel it's as long as it needs to be. Hope it helps.