Linemen are definitely in shorter supply than other positions due to the shortage of guys who are big enough and athletic enough in one package.
The myth though is that we have to go out and get 4*/5* guys. Those guys are great to have but you can build a pretty decent depth chart with upper end 3*s, guys who are 5.6 and 5.7 guys.
Bottom line is that there are plenty of excuses for not recruiting the guys you need out of high school but excuses virtually always result in losing teams. If you are going to win you figure out how to recruit on the lines. If a coaching staff doesn't figure that out they better have their resumes polished because eventually they will be replaced.
Edit: it’s all jacked up after I posted it, see photo.
There are lots of excuses, none of them good. I definitely don't envy the coaches nowadays, they have it rough with all this technology and the Lebron James NBA school of, "don't even try to beat them, just join them all." It's all about show, sure you can play at Colorado but you'll be seen at Alabama.
Anyways, more on topic. I wasn't trying to perpetuate the myth you need only 4/5* players to commit to have a successful line. But, if we're being honest, its why Alabama, Clemson, OSU, Georgia and Oklahoma are who they are. They take a LARGE piece of a very tiny pie and let's not kid ourselves here, impact OL/DL are the guys they're hogging to themselves.
For reference (see photo)
TOP 300 4/5* players Total players 86 or above Total 4/5* committed to 5
OT: 25 29 67 6 20%
OG: 11 14 47 4 36%
OC: 4 5 12 2 40%
WDE: 13 13 32 4 28%
SDE: 14 15 40 4 26%
DT: 26 32 66 11 34%
That's scary, I was mildly shocked by the lack of OT's committed to them, they're spread out pretty well, including our own Jake Wray. After those schools 31 4/5* recruits it leaves 77 players across 6 positions that rate in the 4/5* range, 77 players for 125 schools to fight over, yikes. But the meat and potatoes of this argument is building a line with guys in the 86/87 range.
OT: 38
OG: 33
OC: 7
WDE: 19
SDE: 25
DT: 34
There are 156 players in the 86/87 range and an additional 11 are taken by the 5 schools, so we have 145 players across 6 positions. Let's say we have 5 OL and run a 4/3 defense for 125 schools, that's 1000 positional players. Now, I obviously know you don't recruit every position, every year and build your line that way. But let's say you need 1 at every position every year. You're battling 125 schools to land 6 of 145 players. There just isn't enough quality and if I bumped my list by 5-6 teams its scary to see how much of that talent is going to the same places. Hell if I just add Texas, they have 7 of the 264 total overall players.