Limit to number of items in same "slot"?

[Kurgan]

How much does the porter cost who carries your extra gear?

[Bareheaded Warrior]

There is no extra gear!

Heroes are semi-nomadic wanderers going from dungeon to dungeon, popping into whatever settlements they pass on the way to refuel, they don't have sponsorship and support teams, (picturing a servant equipped with a moist towelette on the end of a stick, to dab on the Hero's lips between combat to prevent chapped lips - Heroes may eventually become famous or possibly notorious but not celebrities in the modern sense) if they can't carry it, they lose it.

On a different note:

They specified chainmail and plate mail because it has been done in medieval times, but they tried to keep the game balanced.

I think the issue for me is the way that was implemented, you have plate armour and chainmail / mail armour (two distinct items) that can be combined or worn separately. For me to replicate that in game you make two distinct items Plate and Mail and state that they can be combined, you don't introduce one distinct item 'chainmail' and then a second item 'plate mail' that consists of a combination of one distinct type you already have 'mail' and a second type that doesn't exist as a distinct item 'plate'.

Just do mail and plate and state that they both add one extra defend dice and they can be combined.

Otherwise it just causes confusion ... if I have no body armour and buy plate mail for 850gc then how much would it cost if I already have mail at 500gc and just need to buy the plate - 350gc or 850gc or 600gc easier for these situations to not arise!