Well, Shogun & Medieval didn't use tiles either.
You could place your armies/agents anywhere within each province.

Part of the dumbness of the RTW/M2TW military campaign AI is that it clearly at least sometimes still thinks its working with the Shogun/MTW style drag & drop campaign map.

Could it be that we are returning to something like that? Drag & drop between provinces but with auto-generated terrain based on where you dropped.