My Northern Alliance are all on a wintry base with lots of snow and ice, but my battlefield is the same theme, so win win. However, when i started my next army, Goblins, i went with a mix of forest bases and tunnel bases, (as i actually have 2 goblin armies, one being old Warhammer goblins from Skull Pass mainly, and the other being Mantic new Goblins.
My Orcs were converted fromk and Warhammer, and are my least loved army, and don’t have a theme for their basing.
my last army are The Herd and are all built to sit together and create one big diarama from the full army,
see
Nav’s Tuatha De Danann Mythological War Host: The Herd
for that one