So, the server definitely can't handle that starts of large wars.
But it can't even handle new days when large wars are ongoing. The day starts, you go to your military tab, you click "Go" to recruit tanks and it goes through (if you're lucky). So you click on planes, and then click "Go" and it gives you an error message despite showing that you are capable of a full day of production. Okay, no worries, shit happens. So you refresh. And then you click "Go" again. And again. And again. And again. It's now six minutes after, it finally goes through, and then you find out your opponent got lucky and managed to build tanks, planes, and launch an attack in the time it took the server to quit dicking around with you.
Considering just general updates are apparently too taxing on the server while there is a large war going on, give it some time to process. Having a five minute berth where new attacks cannot be launched would prevent the glitchiness from !@#$ing up wars overly much.