I'd bet the coaches and players thst see this letter aren't overthinking it near a as much as some here.
Most probably don't. But there are those who would. My high school coach is one of those who would take into account the quality of the letter.
In the grand scheme of things, this letter isn't going to prevent players from going to Auburn. But you also have to consider that this letter is not going to cause players to go to Auburn either. By itself, it's relatively insignificant, but that still doesn't excuse making a half-assed attempt.
My only gripe is with the lackadaisical approach that resulted in a letter of poor quality. You can argue that the letter keeps Auburn in the minds of these schools, their players, and their coaches, but what if the letter leaves a negative impression? Visiting a recruit also keeps your program on his mind, but if you show up knowing nothing about the kid and you speak like a bumbling buffoon, then it's going to leave a bad memory.
My opinion on the letter, and on any recruiting matter, is that if you're going to bother doing it, then do it right. Don't just assume that coaches and players will overlook your lack of professionalism and grammatical abilities. Don't just assume that all of the pretty awards on the colorful letterhead will distract them from your childlike prose. Don't just assume that sending them feces in a box with an Auburn logo on it will keep your program fresh on their minds.
Make every impression count.