I think a war planning team is a great idea, for the reason stated multiple times before: most people who want to help also want to play.
I do think EC should either be designed by war planners and be public or designed by WMs during war. I lean towards the latter. The former would remove the excitement of ECs. Having said that, keep the ECs simple. No necromancy (dead teams fighting alive teams), no hate (like the +10 discard bomb from a few wars ago), no win-more (If you will all matches, gain 10 relics or other bs).
And get rid of SEC. Worst idea ever implemented. At least if you screw up an EC, you only screw up one round. This one screws up 3 rounds. Anyone who thinks SEC is a good idea probably also thinks the ECs previously mentioned are a good idea, thus their opinion should be ignored. Still salty about war #11 SEC.