I prioritized xbows and infernos, but only to level 3 for the xbows and level 2 for the infernos. Then I did mortars as I am still farming. Currently working on teslas and going to start wizards next.
For me for the cost of level 4 xbows and level 3 infernos, I would rather do some of the cheaper stuff first. I still try to keep all my builders busy. I have offered them power tools, but they refused....



