Although I'm not a AlSal fan, I really believe Webb NOW has a shot at breaking the American 5000m record. I thought for sure when Webb ran those 5k/10k times a few years back he race more at those distances, realizing his potential to break 13. For whatever reason, it didn't. Sal is probably looking at Webb's ridiculous range (1:43 800 to 27:38 10k and being a very competitive cross guy) and is looking at the potential of Webb tapping out his potential at the longer distance (5k) that was clearly abandoned under Raczko. This doesn't mean he'll abandon the mile (see Rupp) but that Sal will probably transition him over to specific 5k type training.
At the end of Webb's career, I'm guessing 3:46 will be his lifetime best for the mile. Either way, Sal has to be the luckiest coach in the US since Bowerman, having access to the best training resources and most talented athletes in the country simultaneously.