Disbanding the last defender of a city is usually bad advice, and should only be considered as an absolute last resort. The immediate

penalty may give you unhappy citizens, which are a DRAIN on your economy. The best way to get out of Strike is to put citizens to work on productive tiles, preferably cottages. Taking the attitude that you can "whip a defender later" is probably going to get you into trouble. Population is the SOLUTION to your troubles, and you should not be whipping your population unless you are in danger of breeding unhappy citizens, or you are whipping out buildings that yield immediate economic benefits, like Courthouses, Markets, or

buildings.