Doesn't seem like any other resources are read into the tactical engine at all, besides mana and shards.

Maybe that's why spellresourcecost doesn't function in tactical combat when you use it for anything but mana.

I'm sure I got one of my own resources working with spellresourcecost in tactical combat. I had one spell that killed one of your own units and granted you 1 soul, which was a global resource. I had a second "spell" as the basic ranged attack for a staff which cost 0.1 souls to attack with and it worked fine. Left combat, entered new combat and could still use the global resource. Also if the resource ran out the staff would not attack as expected.

I'll post the xml I used when I get home, but like LightofAbraxas I couldn't get it to actually display in tactical combat which is why I shelved the idea for the time being. I think it has something to do with a <Global> tag in for the resource that has to be set if you want it to be used in tactical. That and maybe the tag which makes the resource a store (like materials) rather than a per turn (like shards).