I think he was talking about the player having hoards of full stacks, but that's just a guess, mainly on the basis that the AI always has hoards of full stacks in most EB campaigns (and most RTR campaigns, best I can recall). And I for one like to assault cities every now and then. If I wait it out, reinforcements might arrive, or my army may start to lose too much of its morale (or get sick!), so I regularly attempt an assault. After all, there are plenty of city assaults in ancient history as well. Its also been my observation that you have little choice but not to campaign in winter--moving your generals what few movement points they may have regularly ends in getting him sick, and all for relatively meager advances.