DeletedUser
Guest
Village Structures:
10k/10k Spears/Swords Split
This is by far the most efficient setup in terms of farm space. There are two downsides however. First, it takes a very long time to build. To be exact, with a lvl 25 barracks it will take 45 days to build, in this game, that is a long time. Secondly, moving troops around is slow. When villages are clustered together this isn't a big deal, but the further apart villages are, the more problematic this becomes.
8k/2k Spears/hcav Optimized Defense
This is a highly popular model of defense. Essentially, you sacrifice 20% of your troop effectiveness in exchange for a faster build time and faster movement. In contrast to the 10k/10k split, this configuration only takes 17 days to build. This is a THIRD of the time required to build the first configuration.
How did you measure the 20% loss? My simple simulator experiment shows that a 6000/3000/235 attack on a 10k/10k village results in the defender losing 10,326 farm spaces (1.1M resources); the same attack on a 8k/2k village results in a defender loss of 15,740 farm spaces (2M resources).
I realize there are other things to consider when determining "troop effectiveness", but I wonder what measure you are using to come up with a loss of only 20%.