Indeed it is a bit broken. However, to answer your question on page 26 of the SPQR rulebook it states under the Helmet entry that “… a helmet cannot be combined with other types of armour except a shield (it is assumed other armour includes helmets).“ This includes Leather Armour. When I started playing I had assumed you could stack helmets with an armour which would have explained the Leather armour cost, but alas, ‘tis not true.
In the FAQ there is a question on page 2 about the equipment cost of Leather, Helmets, and Animal skins. They ask if the cost variance is intentional despite all three having the same armour value. Warlord answered “It is- the spread of warbands they are available to differs”.
I have played with all of the armour types and have experienced mixed results. It’s difficult to determine wether or not heavier, bulkier armour is worth the cost. Despite it’s cost, more heavily armoured troops do last longer in a fight. When I play Brits vs. Caesars Legions, for instance, the Brits can hit hard but if they don’t break a unit of Legionaries quickly they get chopped up in a sustained melee. With this same example, if you take Warriors skyclad, and dual wielding, and take more than 10 in a unit they charge with an incredible amount of force. The trade off is armour.
Hope this helps.
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