I suspect the opposite would happen:
~ Otto and a lot of German nobles and fighters die, the cohesion of the German tribal duchies mnight be severly compromised. The whole Ottonian, Salian and Staufen eras might be butterflied away, with the duchies developing directly into rather independent principalities. OTOH,. a smaller *Germany might be more cohesive.
~ Instead of the East Franks, the West Franks/French unite with Burgundy and Italy, morphing into a HRE. But over time the conflicts with the papacy, with ambitious nobles chip away the power of the emperors. They have to secure their nobilities support to cross the Alps and get crowned, to cross the Pyrenees and fight the Moors. Maybe the Peers de France (Normandy, Burgundy, Guyenne, Champagne, Flanders, Toulouse, the Ab of Reims plus five bishops) develop into similar like OTL's German Prince Electors.
~ Regarding the Magyars: Might happen to them what had happened before to the Huns and Avars: After a victory at the Lech, they remain a plundering nomad nation, spending their manpower over he decades until they are burned out a century later and are forced back to the east or thouroughly subjugated by the next wave of nomads arriving? (That would be Pechenegs or Cumans, probably?)