i believe you are confusing early and late migration of both Hunnic and Bulgars historys
it is better to look at them as conglomerations rather than specific ethnic identities. In otherwords, get out of 21st century mindset and enter the causcauses of ancient times,
you mentioned example of states, they were not states, they were regional aliance of like mionded tribes
they were Hun succesors states in that they replaced the great Hunnic empire
but the Huns, as an ethnisity were long since gone. Outside of the leadership, very few actual Huns ever made it to europe. this explains why the Romans so feared the conical shapped heads of the hun warriors but practically never saw them, most huns had settled by 2nd century bce and only raiders contionued to move westward. The raiders took with them conquered tribes, vast majority of which were Bulgars bvy ethnicity
The states you mentioned had Hunnic rulership, but
They were populated by Bulgars as well as other discplaced tribes.
Bulgars are in fact a conglamoration of or mix of tribes. This is important
We in the west have forgotten their significance, and instead give more significance to names like attila.
This has changed in academia as we are starting to understand more about the composition of eastern tribal history.
As far as the northern, Volga Bulgars are concerned, they come to the picture much later on
At any rate, Its your effort in reconstruction that matters, I will be happy to see your interpretation.