Remember, FCS schools can sign kids to "Partials", so that will help, especially for the locals.
Regarding you statement about "Walk Ons", that is not a funny or weird statement. We all take walk ons for one reason or another. Last year McNeese's starting tailback was a 5th year Senior who started out at McNeese as a walk on. We have had MANY good walk ons that did not get offers for one reason or another, and then later earned a scholarship in later years.
Most of the time, it is because a good player may have been playing out of position in High School, and did not turn any heads as a HS QB, but later turns into a pretty good DB or, a RB or something.
And I do not doubt you have some kids on Campus NOW that could play. MANY times kids don't sign or make an effort to play college ball simply because they do not want to leave home, a girlfriend, or their buddies. I would be willing to bet Lamar ends up with a dozen or two players from Campus in year one.
Even if they never play, Lamar will need a practice squad.