The big tragedy with Sulla is that he was forced to do some things that continued the process of the downfall of the Rebublic.

He certainly knew in 88 that what he was doing would change Rome permanently. Ofcource, he was right because Sulpicius -and Marius- had usurped the senate´s prerogatives and passed legislation with violence. The big difference with Sulla and Caesar was that Sulla was the Senior Consul of the Senate and People of Rome when he marched on Rome.

He tried to do things politely, ordering his troops to behave. Passing legislation in the assembly to curb the tribunes rights and repell the leges Sulpiciae. Its fairly sure that Sulla did have support for these actions from the senate and equites -for Marius and Sulpicius threatened property rights. Marius and co. was pronounced hostis.

He then had to leave an unstable goverment in Italy and go fight Mithridates before someone caught him. Italy was in a state of civil war as soon as Sulla left; the sorry bellum Octavium.