Well, even without Tannenberg the Order will still ahve the problem of rebellious cities and nobles. That became a greater concern in the Thirteen Years War that led to teh dismantlement of Order Prussia, but it already was quite, quite a problem before. The Cities and established nobles wanted autonomy and/or particpation in the political affairs, which was dictated by the Order alone without much "native" in put - and that meant members recruited in Germany. Of course, a victory at Tannenberg gives the Order breathing space to clear its house, but its not like they had done so all the decades before... and without reforms, even a victory at Tannenberg will only give the Order some bought time, I think.