I just happened by and saw you mention you tried making a mod for AJE.
There is a Charlemagne mod for AJE:viewtopic.php?f=316&t=53090
PS - I can't even win these games on the easy settings let alone understand how to install a mod. I tend to play a few turns, get despondent at my losses, read a bit of history and think I'll try again some other day.
I must have played the AACW Manassas and NCP Waterloo scenarios a hundred times.