Most units under the SOCOM umbrella also don't go through the same supply chain. Many of these units don't have an MTOE or any S-4 requisition forms. They just have credit cards with no credit limits. They want a gun, they contact the manufacturer directly and ask for Gun X with Modifications 1, 3 and 6 and said weapon gets front-loaded in the build queue and is immediately built and shipped-out. Aside from Tier 1 and SOCOM units, the only other group that gets that luxury is FBI HRT. When you're top of the food chain, you can do whatever you want. It pays to be the apex predator.
The rest of us don't get that luxury. Nor would I need it with the M9, because for the military, the pistol is a secondary or tertiary weapon system. It's truly a SHTF weapon for all non-MP(& SP/MA) personnel.