Check your assumptions. The Franks weren't a "small group", weren't "uncivilized", and weren't "wandering" anywhere. They were the native population, descended from the Gauls, with a long history as a Kingdom under the Merovingians.
What's amazing is that a small group of uncivilized barbarians out of Arabia could destroy, subjugate and co-opt the heart and cradle of Christianity, from Anatolia through Alexandria.
And, best of all, we here at FR are NOT embarrassed to use the term "DARK AGES" because, as it happens, the climatological disaster that occurred circa 538AD actually darkened the skies.
The term doesn't derive from some climatological occurence. It derives from Victorian era historians, like Gibbons, who romanticized the Roman empire. Well, guess what? The Roman empire never "fell". It simply broke up into successor states and dwindled away, starting with Byzantium. and ending with the Visigoths absorbing the pitiful remains. In fact, one of Charlemagne's claims to authority was as the rightful successor to Rome, by authority of the Pope.
It's not a matter of "glorifying" the Franks; it's a matter of giving them, and the rest of early medieval Europeans their due. There wasn't some blank spot located between Rome and the Crusades, where time stood still.
BTW, there was no "blank spot" either ~ just very few people. And, according to contemporary accounts the skies were noticeably darker and the Sun was always red.
According to the Bretons their first forays into Brittany (as they fled Brittain to escape the invading Angles and Saxons) revealed that no one lived there.
Their own traditions were that people lived there ~ but, alas, Merlin was forced to replant all the vinyards since without people domesticated grapes had disappeared from even the Breton march state now known as the county of Beaujolais.
I'd just bet you are one of those people who continues to believe that all that happened was the fall of Rome. In reality, Rome fell nearly a century before this event. People North of Rome began having a very difficult time making a living and finding enough to eat. Virtually every burnable thing was consumed by fires as folks sought to get warm and evade death.
To the South they had the Plague of Justinian.
Now, about the handful of Arabs, they were far from being uncivilized or few in number. In fact, the early Moslems readily converted the population of Petra and drew on the largest extant population base in the Middle East (outside of the city of Byzantium).
They also paid salaries to Byzantine armies who converted to Islam en masse.