I am new to this game but I am enjoying the club war feature a lot. I can see these are not universally enjoyed and have a couple of suggestions that could help:
Introduce a feature that would allow Club Presidents to opt into wars (or out). This should be visible in Club information so members know if it is a club that wars or not. This would mean that the other admins cannot initiate a war unless the Club President changes the setting.
Allow Club Presidents to set frequency of war for example every war, every second war, once a week etc.
Individual members could be given the ability to opt out of next war if they will be unable to participate. When opted out, members should not appear on the war map or should be automatically shielded for the full war.. To avoid abuse of this feature, I think that the ability to trade with other club members who are warring should be turned off for the duration of the war.