Please forgive my ignorance but the above section has me baffled. I get most of it but where it says roll higher than the bases defence dice which is in the profile in the lists yes so far so good. However what is the
Light armour 6
Heavy or partial plate 5
Plate or cataphract 3
There is no armour 4 for instance and as an example a base of late roman legionaries are defence 5 but put them in light armour(+2) to the points value and it gets worse by going up to 6 if im working out correctly. The negative modifiers i presume lower the defence value to make the base tougher.