I think it sometimes important to remember that not every territory strengthen a state, let's imagine that in 1815 Netherlands had only gotten Flanders, while Wallonia and Luxembourg was given to Prussia. The result would likely have been that there wasn't a Belgian revolt, and Netherland would be much bigger today. In the same way taking a lot of territory which takes a lot of resources to defend doesn't strengthen the Ottomans, it force them to use resources, which could be used better elsewhere.
Maybe the fact that Ottomans outsource their conflict with the German Emperor to a vassal (which can ally with other Lutheran states), would enable the Ottomans to conquer Persia.
Maybe the fact that Ottomans outsource their conflict with the German Emperor to a vassal (which can ally with other Lutheran states), would enable the Ottomans to conquer Persia.