Slitherine

So when ya start a Campaign under Advanced Options there is a Custom Army options that allows one I think to make an army from scratch but it seems to still put units on the board when I start the Campaign but then I just click on disband all an it gives me some more prestige to spend ... is this the way to get this option ...

It's working as intended by giving you a turn 0 deployment turn to customize the starting force.

Indeed. You still get the same starting force even if you select the Custom Army option, but on that turn 0 mentioned by nexusno2000 you can sell units you do not want for their full prestige cost and get others to the point you can just sell all of them and rebuy whatever you feel you want. Still I usually just slightly edit the composition, since if you sell all you might end up being a few points short for what you want - all artillery is quite expensive in the beginning.

Brilliant