Uses of Indie Soldiers?

[Spacepain]

Asides from the sage, which is the best unit for researching magic in the game, what other Indies are of any use?

I've heard mention of indies several others times as a mean for some nations to expand during the early game, however, Its remained a mystery how you go about doing it, and why.

First of why use indies to expand, almost always your own troops are better, higher moral, attack, defense etc. and you can build your troops faster because of the fortress located in the provinence.

Secondly, how do you build the indies in sufficient quantities to make them of any use? There aren't any fortifications so production can be very slow 2 or 3 units per turn.