I don't understand why we aren't able to use defenses/barrcaks/spell factory/heroes while they are upgrading, but we can still use army camps and troops that being upgraded in the lab. I suggest that SC be consistent about this, and disallow use of any troop or building that is being upgraded. This would also help them make money because people would pay gems to speed up their army camp upgrade if they couldn't use it, and would probably also pay to speed up troops that are needed for war.
