I just devised this relatively simple method for those who would like to see powerful heros or other certain 'individuals' represented on the battlefield.
Since there is a hardcode on the minimum amount of men in a unit we technically cannot have less than 6. To get around simply make a new unit with the entire texture map alpha'd out, so that they are totally invisible on the battlefield.
Now that everyone is invisible it would apear that the unit has no men, unless we have some officers, of which we are allowed up to three I believe. This allows us to create units with less than 6 men, with a maximum of three and a minimum of one.
If you were wanting to make a lone hero type unit simply do the following, plus any other necessary adjustments:

-create an invisible unit model as well as the desired officer hero model.
-create the two necessary entries in descr_models_battle.txt. One for the invisible model and one for the hero.
-create the necessary entry in the export_descr_units.txt. Make sure that the unit you created is the invisible model and that the hero model is set as officer.
-create the proper description entries as well as unit card icons to represent your hero. Instead of the picture of the unit you could use a portrait so that your unit looks for FM'ish and more eye-catching and important than regular units, because really the only thing visually differentiating the FM's from the regular units in the game are the portraits..

Thats basically it. Your unit moves and acts as any other regular unit on the campaign map but has the apearance of an FM unit. On the battlemap it works like any other unit as well except it would have to be made apporpriately uber in order to compete.
Of course there are some side effects since we had to essentially cheat the game engine to get this done, but they are pretty minimal:

- the invisible part of the unit will still have weight, volume and attack value, as well as the most notable effect of casting ground shadows from the invisible soldiers. This can be minimized and is hardly noticable as long as the unit size is set to its absolute minimum of 6 (so you may have to play on normal unit size setting in-game and offset that by adjusting the normal unit level sizes to be larger in the export_descr_unit.txt file)
- since this FM styled hero unit is really just a regular unit it wont age or die of old age, so it is essentially immortal unless it dies in battle; this could be a good thing or a bad thing depending.

Hope that helps anyone batting around this idea. I know its been mentioned a few times now and for some reason this idea popped into my head so I thought Id mention it.