Question about how the army should be...

Let's say you are around 1k -1,2k acres with 20k army

50%/50% def specs and elites

Have done some calculations and figured you will get more off per networth having 25% off specs and 36,5%/36,5% def specs and elites...

Difference in def when sending same offense out would be around 3,5k only

So why is everyone going 50/50?