I've seen that, but still think it's coming. There is probably an elegant solution where the heroes are simply available in war raids notwithstanding that they're sleeping/upgrading, and that the heroes don't need to recharge after war attacks.
Other solutions include putting upgrades into lab/new building ("armourer") would mean that heroes are available for all raids while upgrading (albeit with usual recharge time). I kindof like the armourer idea, with possible additional uses of the building to do other things like customise hero appearance.



, but who knows if they're working on it or not
