So, normally, the breakdown is 50% of the XP from the battle goes to the general, and then 50% is divided between commanders proportionate to the number of units lead.
I’ve decided to alter it to include lieutenants, calculated as commanders leading one unit. This allows some XP to funnel down to henches and lower level PCs who can’t quite be commanders yet, and also it just seems appropriate that commanders can arise from lieutenants over the course of a campaign.