With the NIL and unlimited transfer portal, coaching is different. It won't be a surprise to see previously successful coaches struggle. I was looking at a preseason magazine and most of the G schools are getting wiped out every year. Here are the returning starters in the American conference (including kickers):

Army 14
Navy 11
Temple 11 (7 were from a relatively anemic offense)
FAU 9
Tulsa 8
UTSA 7
Charlotte 6
Rice 5
Tulane 5
USF 4
ECU 3
UAB 3
Memphis 1
UNT 0

The coaches are now going to have to be able to bring a disparate group of players unfamiliar with each other into their system, which is probably new to the players. And then they have to get them really ready to play in just a few games.

I suspect it means the complicated schemes will start to get simplified.

There's no long term development of players and culture. You have to start from scratch each year.

In the long run, the service academies will benefit. They weren't likely to move up to P4 where they would be faced with bigger and stronger opponents anyway. And they aren't likely to suffer from being poached in the portal.

The sad thing about the number of returning starters is that most of those are players that aren't attractive in the portal in the first place. The talent gap between the P4 and G6 will only get wider.

Football is becoming like basketball, with big roster turnover for all FBS schools. A4 are a little better off on retention, but they too are wheeling out new lineups every year. It's impossible to do the old build from freshman signees that was favored by schools like Clemson (Deebo), Iowa and Utah used to do. It's all about portal transfers and budget. It's like the NFL player acquisition on steroids, scouting every one of the 135 (non-academy) FBS schools, or for the G6 all the FCS schools, for anyone they think can help.

Depth is an issue, especially at QB, as every top 40 QB is almost certainly going to different schools, most of the next 40 even starting at G6. If you lose your top 25 QB at a contender, it doesn't mean a top 50 QB comes in, but likely either a completely raw bench warmer or some guy outside the top 100 with serious problems seeing the field and delivering accurately. (I see that at Ohio State with Sayin going down, a QB only in that 15-25 range, being replaced by a guy who appears to be a deer caught in headlights; and this isn't the only school this has happened to this year.)

Kirby Smart sounds in pressers like he hates this and might soon join Saban in the TV commentator world instead.