Drunken, when you have a 1:1 ratio of defensive and offensive troop buildings, plunder can be considered to be boosted by 2.5% for all troop buildings instead of 5% for half of the troop buildings.
Also, Res is correct and I have pointed it out many times in the actual thread, this only happens when both build types are at equal troops levels. This means that if you're fighting from a pinned state, mixed is better. From a full unload, balanced is also slightly better. It's completely about your own play style.
Finally, I'll change that cyan sometime today, I know it sucks to read :lol: