No it is not unusual for Top Athletes that have speed, agility, and size can become a Linebacker. Often Running Backs in High School play Linebacker like PSU Poluszny at Hopewell, also Tony Dorsett actually was Monster Man Linebacker in 5-2 Oklahoma Defense at Hopewell.
The Bigger Players that have size and speed can easily adapt to Linebacker and te\he smaller one often becomes a Defensive Back like Revis did when he played QB and multiple positions at Aliquippa.
Russ Grimm that played QB in College told Jackie Sherrill he will become a Linebacker until Jackie told him no you will become an Offensive Linemen, Russ objected and Jackie told him, this is up for discussion, son. Russ attributed that Jackie in his OF Speech and changed his life and made him a better Player.
The facts are often QBs, RBs, TEs, and WRs in High School can easily switch to Linebacker and Defensive Backs. But becoming a DL & OL takes more time and building up the body.
Being a LB involves reading the backs, dropping into coverage, reading OL blocks and breaking blocks while reading the play. Also being able to remember the playbook as a MLB you would be pretty much the leader of the defense.
Linebackers have the speed, strength, and studying the Offensive schemes of other team during prep week. Linebackers need to predict and practice what happens on a counter play, or what the full back does on a pass play, or what play they run the most of out of a 3 Wideout set, or when they motion the TE to the opposite side.
Coaching prep and sideline game coaching is very important because the Linebackers must constantly adjust to what the other team does in changing their own Game Plans during the game. Often Half-time Adjustments that win a game is because the reads, adaptability, and changes made at Linebacker Coverage. The Linebacker must be fast or quick enough to be able to cover the runs and short passes, plus pressure and Biltz the QB!
It requires an Athlete that may not be fast enough to be great WR, or can't catch as well at RBs or lacks vision in running, as well can't catch or run pass routes as other Wideouts, but because they were RBs and WRs, can react and make reads and most importantly make the tackles that disrupts the Plays by being a Linebacker instead of being Back-Up at WR or RB. It is an opportunity to play right away.
Often Linebackers in High School can become DE or DL in CFB and then go back being a LB in NFL. This is what Hugh Green, Rickey Jackson and Chris Doleman did and quickness and mental smarts reading ahead of time allows disruptions of Offenses.
