For that I think we'd need Philipp the fair to live longer.
The only reason I say this is because I'm not sure how much sway Maximilian I had over Charles, the marriage treaty was organised in 1515 and I think by then Charles had been granted/had his majority recognised as a compromise with the local nobility with Maximilian (and some French input as well I believe), same thing had happened with Philipp the fair who's majority was recognised when I think he was 16, so Maximilian wouldn't have input in the affairs of the low countries. I guess it was easier to arrange for Ferdinand a minor (he was 12 I think) than the emancipated Charles who could reject it. Also according to wikipedia, Charles was under the sway of William of Croy (https://en.wikipedia.org/wiki/William_de_Croÿ), who manoeuvred this emancipation and influenced him away from his aunt, Margaret, who'd been appoint regent on Charles's behalf by Maximilian. William would go on to convince Charles to cancel his initial engagement to Isabella of Portugal for Mary Tudor among other things (which was later shuffled back again later, probably wasn't hard to convince Charles he's not married and so he sowed his wild oats, he had like 3 kids before he married Isabella; William overall seemed a decent advisor though, you can follow his rationale on somethings)
If we make that alteration with Philipp the Fair (man his picture on wiki looks ugly) could we end up with the end result split I was looking for?
I'm just interested in the idea a big Spanish contingent trying to relieve the sieges of Vienna and fight the Turks in Hungary.