In the end, I think Madison and Hermann get it backwards. Entertainment for hockey fans is just about the ONLY reason to support this stadium deal. Because using a stadium to provide "economic impact" has been tried in a lot of places. And failed.
AntiRust makes a strong case against the Madison-Hermann proposal, citing a Brookings report on the economic impact of stadium deals, that the promise of more tourist dollars (among other things) creates false expectations. The public return on invest is nil to negative.
I think Madison and Hermann are offering a somewhat novel approach to squeezing some regional benefit from keeping the Penguins in town. There might be a bit of tourist boon to the area if you can figure out how to attract out-of-town hockey fans to watch the Penguins in Pittsburgh.
I know from experience, that there are various barriers that prevent fans from afar making the pilgrimage to Pittsburgh to see their favorite team live. This kind of journey could be better facilitated, with the right kind of marketing research and outreach. The process starts with a clever campaign for the road games, where the Burgh Diaspora is waiting to see Crosby and the new Pens.