The OG issue would be greatly simplified if we just tweaked the OG trait itself - to give it a standard meaning. Under the vanilla terminology OG is said to represent backward thinking and inability to adapt to new ideas, but in very many cases (particularly with Germany) it is applied to 'politically backward thinking' (i.e. unreliable) leaders. So quite a number of leaders who were in fact quite progressive thinkers on military matters nonetheless acquire the OG tag. This is then further complicated, as you say, by hanging the OG tag on leaders according to their date of exit from the army lists - which was very often a political decision.
Sorting all that out would be so much simpler if we used a different trait for the 'less-loyal'.
Sorting all that out would be so much simpler if we used a different trait for the 'less-loyal'.