OK, after carefully re-reading the supply rules, it appears lack of 25% military control is my problem here, as the generals never activated and thus never took any MC in the region. This is the first part of the rules paragraph that covers that issue:
Supplies can be forwarded out of their region by Depots, Level 3+ Cities, and unblockaded Level 3+ Harbors (or Naval Bases), and these also demand Supplies. Supplies can be forwarded to structures and Units that need them and are not besieged or blockaded. Supplies can’t be forwarded into or through a region where you have less than 25% friendly Military Control, and enemy troops can block supply routes through (but not into) a region.
Where my confusion comes in is the second part of the same paragraph. When reading it, it reads like an exception to the above rule because it talks about drawing the supplies instead of forwarding them, but obviously it is not and the paragraph is poorly written.
Thus military Units can only draw supplies from supply sources or stockpiles (including a Supply Wagon) in the same region or from supply sources in an adjoining region meeting these requirements. National troops receive supplies to fill their need first, then allies and countries with supply rights get their share.
In fact it is probably misleading as I don’t think supplies ever get drawn in the AGE engine, I think they only get pushed or forwarded along the chain. So the 25% MC issue is only ever checked in a destination stack’s region, never in a supply source region as the second part of the rule paragraph seems to imply.