I can explain how you get EFF this high
i did july with 5,3eff and 100k units killed it means a lot colonies done and its my avr eff but not best what i could do cuz start wasn't that well. So eff counts as you know 100 killed with 20 loose to get eff 5. To do that you just need kill sector leaders and boss the rest camps counts as killed too, for eff but it doesnt count for XP. So there is to ways how to play PVP to play for EFF or for XP you decide yourself. So most player who have high eff they look for, most time small colonies witch they finish with lets say 1-3 camps killed. The rest they just block and use all medic pack. In end they have just one alive general with all medic pack used. As for Tip i offer try to kill boss first then you can go around and kill the rest leaders from back sometimes without even block.
And for those who want to get water castle first kill as much units as you can and dont care about EFF