Would relying on town militia be a sign of desperation?
Short answerUsually by this stage of the campaign: militia can help early, but later they mainly inflate numbers without providing equivalent fighting power.
NotesWithin the campaign, town militia mostly make an army look more numerous than it really is. They can be worth building early, when resources and recruitment options are limited. By this stage, they are a poor substitute for stronger troops. The exchange separates headcount from combat value in the game's force model.