[Dedas]

If I'm very unlucky and the adjacent provinces to my capitol are barren wastelands, I would not build my second fortress so close. This is rarely the case though.

I have found out that getting that second fort up and running as fast as actually possible helps Ulm immensely with both expansion and research. I would even go as far and say that it is in fact necessary when Ulm against great players.

Good fortresses is one of the thing Ulm is good at so one should try to maximize that. Do not go for the cheapest fortress but rather the best mix of administration, cost, defense and build time. In Ulm's case that would be the citadel and to peg-castle. If placed correctly you will get great many resources and awesome defense, buying you time to get your slow troops into position if you are attacked.