Hmm i am thinking if it is possible to add and tweak some items to the shops? What causes that fighters are a rare view here is the lack of proper equipment for them... for example recently i had great problems with buying bottles with holy water and actually without a help from a dm, that would be not possible to acquire.
I know that there are silver and cold iron weapons, i do not know though if there are silver coated and cold iron forged ammo types.. it would be also a nice option to allow holly water to be applicable on the melee weapons and not only be a grenade like weapon. It would be a great addition if there were different power types of items like acid flask, alchemical fire, holy water,choking powder, tanglefoot bag - so for example we would have two more tiers that would cause more dmg and would have longer durations if applied on weapons (for example tanglefoot would work for 2 rounds, basic, improved 5 rounds and mastercrafted 10 rounds.... alchemical fire would do basic 1d4 fire for 3 rounds - basic, 1d6 for 6 rounds improved and 2d4 for 10 rounds - mastercrafted if applied on weapon, and as a grenade it would be 1d6, 2d6 and 2d10 respectively). I am not sure if I've seen ammo type that could be made to fight undeads, for example a bolt that is blunt but with holy water soaked clothing around it.
Well i hope that you get the idea
