Is there anyway to replenish a the general's units?

[Togakure]

Sure there is, at least in vi 2.01.

First, you can retrain the unit by opening the production queue (in a province that could otherwise produce that unit type), and drag the partial unit into the queue. It will be replenished just as if it were a new unit being produced. I'm pretty sure you can do this willl any unit (though maybe not a royalty unit, e.g. Kings and heirs).

Second, if you have other units of the same type, you can take men from one and drag and drop them into another, to make a full unit. It's kinda weird how this works, as you have to click and hold the source unit, drag it out of the box at the botton of the screen, and then over the target unit that you want to top off, then release. Note that, if the two units have different upgrades, the TARGET unit's upgrades will result. If you have a unit with no upgrades, and drag-drop men from it into a unit with armor upgrades, the full unit will have the armor upgrades and vice versa. Valor is averaged between the two units, so it is possible for the resulting unit to have lower valor.

You can also select a stack and hit M (merge), which will combine partial units as much possible, or click on the entire province and hit M, and units in ALL stacks in that province with merge as much as possible (and get all mixed up, which can be annoying). If you have the "Tidy up units after battle" option on, this merging happens automatically (which really annoys me so I turn it off).

[Philippus Flavius Homovallumus]

You can retrain Royal units, except the King. The probelm is that if you retrain the Crown Prince and the King dies that turn then the game crashes because it thinks its retraining a unit that no longer exists.

So be careful!

[mikkele]

You can retrain Royal units, except the King. The probelm is that if you retrain the Crown Prince and the King dies that turn then the game crashes because it thinks its retraining a unit that no longer exists.

When a heir ascends to the throne, his unit is automatically replenished to 100%. So if your King is ailing, there's actually no compelling reason to retrain the Crown Prince's unit.