Slitherine

I was thinking this would help far flung areas. An encampment would take 10? turns to build and require at least one of all the resources. When built you would place the encampment on a province. The only benefits is troops housed at that location are halved for upkeep costs, like the capitol. If the unit was made elite they would be limited to 4.

336 hours

Seems like a decent idea to me

Due to it's proposed economic bonus, perhaps it would be an Outpost.

Another thought is that it would function as a lesser Capital in terms of economic fall-off of provinces as they lie further from the Capital.

That would be nice - kind of regional capital