As someone with more than a passing familiarity with the funding model
, let me provide a bit more information:
At the sub-unit level, attendance is assumed to be 90% for MCpl through MWO, and for Lts through Maj. Ptes, Cpls and 2Lts are assumed to attend at 80%. However, the 37.5 days is increased for MCpls and above, as there is a "Command Presence" factor applied- essentially, the assumption that plannign and preparation requires additional time and effort.
The problem ,of course, is that the current reserve establishment totals roughly 25000 positions, with funding for 16000. The less than elegant solution is to pro-rate the funding determined for each area: If Land Forces Southern Area, for example, has an establishment of 5000, and a target strength of 3000, the funding required for the 5000 is multiplied by 60% (3000/5000) to determine how much gets allocated to the area.
Hopefully, the current review of the Army Reserve Establishment will lead to a much more realistic establishment that will let units be properly resourced.