I don't know this for sure but I would guess retailers like Leffot and Leather Soul sell more Alden's than J Crew. Also, J Crew focuses on selling models that aren't that rare or that have ample raw material available. It's not like J Crew is hoarding whiskey, cigar, or ravello models. J Crew has fewer stores overall than you think and their men's business is very small compared to the women's business.
To add to this, only the Manhattan and downtown Boston J crew stores have "on hand" Alden models. Everything sold by J Crew Alden besides that is online.