Seems like a pretty broad stroke you've painted there. No two folks are the same, ergo no two football players are the same, in ability, acumen, measurables or any other way you wish to measure them.
That's not to downplay the leg up kids get while getting that spring practice and summer with the team but to discount out of hand the ability to contribute for August enrollees seems a bit reckless to me.
Lots of truth to this. Great for a juco to come in for Spring but some can still make a difference quickly regardless. Another major consideration is that Flanigan is a linebacker. Usually a MUCH higher learning curve for a LB verses a DEnd/DT. If you are physical enough on the line with good technique you can acclimate faster than a backer learning the D and adapting to speed of game where you are just reading and reacting quickly