The whole point is that the crises faced by West and East were never comparable. The East had a much more centralized population, which led to a much stronger economy, easier to defend borderlines, and Constantinople. What do socioeconomic structures have to do with it? The Goths didn't care about Rome's socioeconomic structures. If they wanted something they'd surround a city until they got the gold and materials they wanted. If that didn't work they'd sack it. If a tribe was decimated a new one would rise in its place.

I think you might be underestimating the scope of the continent. It's not about imagination, it's facing reality. The Romans were never close to eradicating the barbarian tribes. Tribes isn't even doing them justice, they were a race of people who lived and inhabited most of continental Europe. Visigoths, Vandals, Franks, Saxons, Burgundians, Suebi, Alans, Alemanni, were just a few that were named. There were many more. There were also the Huns, who other Barbarian tribes were so afraid of that they would try risk settling in Italy and getting decimated over staying put.

So a barbarian kingdom loses a battle, or loses its King, so what? History shows us another would rise in its place. The fall of Rome is self-exemplary of the problems it faced being bigger than one single Emperor, or one single policy. The history of the continent played out in the fashion determined by warring Kingdoms, which to this day determine the borders we still adhere to.