upgrades

[DracoStandard]

at the risk of being really thick

if a line says 'upgrade' they replace the minima and take from the maxima of the original line

I assume thats the case, but I want to check

[lionheartrjc]

At the risk?

In answe to your query - Yes. 

So

Spearmen 8-16
Upgrade spearmen Any

Means that the army must take at least 8 spearmen or upgraded spearmen and cannot take more than 16 spearmen/upgraded spearmen.
Some upgrades specify a proportion so:

Cavalry 12-24
Upgrade cavalry  Up to half

This means you could take 12 cavalry or 6 cavalry and 6 upgraded cavalry (or 8 cavalry and 4 upgraded cavalry).  The most you could take is 24 cavalry or 12 cavalry and 12 upgraded cavalry or proportions in between.

Richard