When the Roman Empire fell and the Germanic tribes moved in to the old Roman Provinces, they didn't continue the Roman way of governing but reverted back to there old German ways of ruling. Why is this so? Why didn't the inertia of the system keep it going even after the Ravenna fell? Wouldnt they be impressed with the Romans and try to emulate this? Was this overall bad or good for Gaul, Italy, Hispania, Germania, and Britannia?
I would strongly suggest reading this response by /u/shlin28.
To sum it up, the Roman government was continued by the "barbarians" that took over as well as it could be. I'm not sure where you got the impression that the Germanic tribes "reverted" to their "old German ways of ruling", because they didn't. Such an assertion also betrays an understanding, regarding the Germanic confederations and tribal groups that took over military and political power in Western Europe in the 5th century, in which they were unsophisticated and backward. This was not the case: they were sophisticated people who did have the capacity to understand and replicate Roman systems of governance, and they did so as well as they could. As to whether the fall of Rome was good or bad, as the above link demonstrates, it wasn't bad for Italy at all until warfare beyond the control of the Ostrogoths wrecked the place. Gaul as we know became the epicentre of Western European power in the form of the Merovingian and later Carolingian Empires. I won't comment any further and on other places because I lack specialist knowledge in this period. But your question is based upon false assumptions about the backwardness of the Germanic successor kingdoms and I can't suggest strongly enough that you read the answer I linked above.
What do you understand by "Roman way of governing", exactly?