Uvs, More Uv's and even more!! 

When creating my low poly assets, I did a number of tests by baking normal maps. The amount of Armour details I had, I figured I would have very little Uv space which would have to be huge to squeeze all the elements in a single texture sheet. I decided to break up my model into three separate parts for maximum quality. One map was the barbarians body, and the other is the Armour split into two separate maps 2K each. 

UV Working Process 

Two separate Uv maps for the Armour.

Splitting the two maps would give me enough resolution to work with.  Even though creating two means more work it would save my lost details if I were to merge the maps.

A reasonably spaced UV map for testing. 

Bake from Xnormal

I used Xnormal to generate my normal maps. It is a very robust program that allows you to generate a low poly cage for your high poly details to project accurately onto the low. It also lets you create an occlusion map, cavity map and a world-space normal map.  

Results in marmoset

UVMap 1 - Armour set 1

UVMap 2 - Armour set 2 

UV Map 3 - Body