Can they capture hexes for the purposes of Territorial Gains?
Do they have a combat value? What happens if an infantry unit engages with a lone General unit?
What happens if two lone General units engage?
Good question that the rules seem to side step. FWIW the house rules I implemented for my first play of this last week are:
1. We played lone generals may not occupy victory hexes for VPs. The rules are vague at best so this was something of an arbitrary decision.
2. No combat value. The rules never speak of one.
3. If infantry engages with lone General we roll the die - 1-5 General is routed, 6 General is killed. I figured giving a free "General kill" roll is somewhat consistent with the game's philosophy for how they die.
4. Generals have no ZOC so they can pass by each other freely but not move into the same space. No battle.