Possible... but pretty unrealistic, for a few reasons:
- The Franks were Roman allies. Of course they could attack the Romans at any time but Rome would do whatever they can to stay on their good side.
- Too late for huge slave revolts in the Roman Empire.
- Alaric was almost forced to invade Italy. His real goal was an Illyrian and Raetian homeland for the Visigoths.
- Alaric attacked Rome because negotiations with Honorius were interrupted by the invasion of a rival he had a blood feud with.
It's possible that Alaric could have decided to have an Italian homeland instead of an Illyro-Raetian one, after sacking Rome and seeing how easy it was, but a massive invasion of Italy before this happens--probably not.
Of course some would argue that Alaric wouldn't even want to keep Rome, even in an alternate timeline. In Relics of Rome some people criticized the fact that I had Alaric stay in Italy.