Using a war priority for upgrades makes efficiently farming with Barbarians and Archers slower, since those two troop types are not given upgrade priority.
Whether to prioritize farming or war efficiently is a personal choice. Our clan supports you either way.
The upgrade priorities that prepare for war are:
TH6 - clan castle 3, spell factory 2, lightning spell 4
TH7 - army camp (a new one), spell factory 3, dragon 2, balloon 4, hog rider 2
TH8 - clan castle 4, lightning spell 5, dragon 3, quake spell 1, balloon 5, hog rider 4, golem 2
