I do see a lot of posts already regarding this matter, however I would like to post this once again to point out one thing.
When Heros are being upgraded, your hero will not defend/attack the base (farming base). But when you go in to clan war you have your hero defending when it's being upgraded but you can't use them to attack(?). I know all this therefore when ever I upgrade my heros I have to sit out from clan war for 7 days since I don't pay money to buy gems for instant finish. This forces me to do nothing for 7 days since I maxed out my base other than farming which by the time when you max out your base gets quite boring.
I ask SUPERCELL make this adjustments as you are putting more focus with Clan wars so people can participate more and enjoy the war while they get stronger heros.
Hero Upgrades and Clan War.
