Halfling are a bit different, in that once DBE is high enough on TGs, you always get better offensive returns on Forts. This is obviously due to their having a 100% elite army. The principle is the same with all races, but it's more obvious with Halflings, as all you have to do is adjust your send numbers to change your defense at home, and there's no variance in unit training. Quite easily the most versatile military in the game at the current time.