I'm not sure if the logistics argument is that clear cut - after all, in 1532 Suleiman was leading a larger army, across harsher and further terrain and against an enemy that had resorted to scorched-earth tactics to stop him, and yet he still managed to capture a lot of what is now Kurdistan, Iraq and Western Iran from Persia. Much better weather than OTL and more luck in Ottoman mining operations and it's not unreasonable to expect the Ottomans to be able to capture Vienna in time to fortify it against any inevitable reprisals, as well as open the Danube (which was navigable by the Ottoman fleet) as a permanent logistics corridor of sorts. Buda, after all, was a key Ottoman base during OTL.