Charlemagne and later \"Roman\" emperors

[Robert Vermaat]

culturally the Roman empire was a main point of reference for them, there simply was no other established state in the west they could refer to for their ceremonies, terminology ecc.

I'm not sure I agree. Clovis' predecessor, Childeric, was content with using the Latin title "Rex" as we see on his coinage and jewelry. The use of "Augustus" is something new for a Germanic king.

Not so much when you know that 'rex' and 'augustus' were already used as a synonym by the Romans themselves at this point in the 5th century. From that point of view this can be a simple case of continuation, not earth-shaking.

What makes the story more astonishing is the near contemporary events taking place in neighboring Italy. Odoacer, the first Germanic king of Italy in 476, tactfully sent back the imperial regalia of the western empire (WRE) to Constantinople, declaring that there was no need of a western Augustus as long as he could rule as a subordinate king.
Then Clovis comes along and does the exact opposite by wearing the regalia of an Augustus and allowing himself to be called such.

As above. Aklso, we do not really know what regalia Clovis used. All we have is a much later account by Gregory of Tours, who was a) not always very clear in his histories and b) a big fan of Clovis.