[Baalz]

Well, without getting into a tangential argument about Ulm surviving an initial rush, as I pointed out this is a total side strategy with a cost of a couple mages, a couple low income provinces, and the upkeep on 20 scouts. Ulm is seldom pinched for gold and also generally has an abundance of the cheap smiths. This is totally something you can do in addition to whatever your main strategy is and doesn't make you noticeably more vulnerable to a rush.