Good point and to be fair,
When Stafford signed with Georgia out of Highland Park, there was no guarantee that he would have signed with UT. He's from Dunwoody Ga., his Dad is a graduate of Georgia so it's not like he was a lock for Texas. He only moved to Dallas in HS, he was not a Texan born and bread and had Stafford signed with Texas, it was not a sure thing that he would have started immediately. Remember, Young declared early so had he elected to stay, Stafford would not have started like he did at Georgia as a Freshman. He would also have had to have beaten out Colt and Snead. While Jevan Snead didn't pan out, he was certainly no slouch as a recruit at the time. He was a Two Time All State QB, a Prep All American, 23-2 as a starter. I don't believe that Stafford was every coming to Texas but whatever.
Same deal with McElroy, he was from California and moved to Texas. He originally committed to Tech and then changed to Bama late. He was not even close to the top QB recruit out of Texas that year. You can make an argument that Texas should have recruited him more but honestly, Snead was regarded as a much better prospect at the time and McElroy was nowhere near as good as Colt was in college so I think it's kind of full hardy for him. This is basically the same deal for Ponder. All those who say that Ponder would have come to Texas are not entirely accurate. Ponder's Dad played at FSU. Ponder was no lock for Texas. He was basically in the same situation as was Stafford.
Now, Chaise Daniels, maybe you could make a case there.
I don't think you can hold any of those guys up as examples of misses by Mack and the Staff. Now the rest, maybe there is a better case to be made there.