Rob:

Another situation may also play into Militia officers attempting to get into regular units. There was a great deal of unrest in the various militia units, particularly those that had been volunteer organizations forced to become militia or disband. The unrest led to more than one serious revolt in 1813 where towns were taken over by the rebelling militia, where the revolts had to be put down by other militia units. You don't see it discussed much.
John William Fortescue writes about them in his The County Lieutenancies and the Army, 1803–1814. I know that there was an effort to push militia into regular service at the time for that reason as well as the shortage of recruits.

Bill H.