I changed my tactics to staying in much higher leagues, medal count from 2200-2500. Once a day, you can get the victory chest (you can get it faster with library research) by accumulating 15 stars. What I do is to use the German UU and quickly defeat TCs for 2 stars earning extra loot and battle bonuses along the way. Why? One of the victory chest rewards you can earn regularly is 16k oil. Other rewards such as 3.5mio food or gold can be used to upgrade other buildings and troops. The advantage of doing such raids, you can get 15 stars quickly with minimal troops losses.