Did you not do golden armor? And yeah deep Forest road is the best I think. Also you should never use irons to lvl units past like lvl 30 it's a huge waste of gold per exp. I normally use irons till 30 then use bronzes till 40 and solider/class bronzes till 50. Unless you have plat armors to use. Also you can awaken Betty or lyla for gold get if you have them