I don't think a strong emperor would have helped any. There were plenty of strongmen to the end there- Aetius and Ricimer stand out. The emperorship was bought and sold- not that that mattered a whit.
Rome was exhausted. It was an ideal, a symbolic legend, but one that had run its course. The Crisis of the Third Century and the Antonine Plague had severely weakened the city and the empire as a whole. The rife internal struggles for the purple wore the army down to where people had to be pressed into service, and other sectors of the economy were becoming so deserted that one fo the emperors had to decree that sons went into the same business as fatehrs. More and more of the military was being made up of feoderati and foreigners. How long can an empire survive when its army is made of foreigners?
The economy was in the toilet. The army was disciplined but tiny, and worn out from near constant warfare. The populace was poor, wracked by the wars (devastation is not just a concept in RTW, passing armies that had no logistical chain often destroyed vast tracts of land in their passage), services were failing, and the money near worthless. Plus the plague wiped out a good portion of the population- recovery was too slow.
And politically, idiots in the Senate thought the purple could be bought and sold, and good generals were to be assassinated lest they aspire to restore the glory of what was once Rome.
The Roman Empire died basically through apathy. Nobody cared enough to keep it going. Those in power only wanted the power and trappings- and could care less about the rest. The people gave less than a rat's ass, as long as they could survive in those hard times. The army didn't care about the empire, only their paymaster.
So there is no clear point where one can say: "if this was different, then Rome may have survived." There was a whole cartload of shit wrong with the empire there in the end. A bushel of things had to be fixed for that to happen. So what could have made the empire survive?
Nothing. It was time to hit the reset button.
[This message has been edited by Terikel Grayhair (edited 12-19-2013 @ 05:36 AM).]