Currently 2 armory slots are just not enough, and while addition of 2nd was a long overdue feature, it doesn't cut it anymore. There are countless general upgrades, 6 levels of each aircraft type per age, then 2 factory level troops per age, and to top it off bunch of barrack troops, tactics and coalitions. We need each armory tab to have its own upgrade slots. One unlocked, one available for 1000 crowns. I will happily buy crowns to unlock extra slots.