Right now i have 24 lvl 3 coe on ll, 10 volary and 5 colony on hl, 2 blood barracks on hf. All my explored lands are built on what would be the cheapest way to get 1m sdt (15 hl explored, 3hf)
The beat bet would be 4 towers on Hl. It might be cheaper to build on LL ( didn't check cost to build) but it would take far more land to do it and kill plunder