So, I've been playing a bit of the Irish campaign on Kingdoms.
I have too much money.

I happened to reclaim an empty English fort with a stack of 3 units, en-route to an army - I noticed that 2 of the units turned blue - meaning (I'm assuming) that you don't pay upkeep, as they are "free garisson" units.

I absolutely LOVE this. I was trying to build a "standing Army" to defend against marauding Scottish / Welsh / Vikings / Rebels.

Instead, I can fill each of the 6/7 forts with 2 man stacks, and I've got a "free" army hanging round, waiting for a reason to pull them together.

Brilliant! And historically sensible too. Anyone else noticed this? I'm always very mean with my armies, trying to keep upkeep costs down, to ensure I can keep developing at a high speed. It's very useful to be able to 'bank' free units like that.