But its what caused their decline, many high officials of the order were killed or taken as prisoners. What I'm trying to get here is what if the Teutonic Order didn't decline and power and according to Wikipedia this battle was one of the main reasons why it began to decline.
Oh aye it was a major blow, but they "survived" as an organization for a while.
See the rest of my reply - they'd probably take advantage of what would be presumably a decisive win (hard to have a light-loss major defeat) to snap up land and money from Poland and Lithuania.
Not sure exactly what land - the Order doesn't exactly have any specific claims that I can think of.
Something securing their hold on the Baltic coast would probably be involved, though.
I'm not sure if they'd continue longer or not - they already have no real reason to exist, which means support for their crusades is going to dry up. That's going to be problematic.
On the other hand, a presumably much weakened Poland and Lithuania might have trouble taking advantage of it.