As I said in my previous post, yes the waters are muddied by a chronic lack of sources all round. Yes, the literature is sparse. But there are some sources that we can work with to paint an approximate picture.
The Russian Chronicle of Kiev written around the 1110s also mentions the Vlachs north of the Danube fighting against the magyars.
I wouldn't just discount the Gesta Hungarorum just because it was written in 1200. Even as late as 2014 the French historian Edouard Sayous in his 'Histoire générale des Hongrois' does not dispute the chronology and events of the chronicle. The American historian Dennis Deletant agrees that some of the details are questionable but does not dispute the overall narrative.
Also, it is established that the ethnonym 'kun' referred to other Turkic people such as the Khazars and the Pechenegs which were present at the time in the area, including in Transilvania. It is generally accepted that the latin translation of Anonymus of the word 'cumani' refers to turkic (pechenegs, khazars, cumans). If we go by your theory, the byzantine chronicles are also wrong because they talk about scythians in the middle ages.
Anyway, I have no interest in engaging in a protracted discussion about the above interpretation. These are the sources that we have and each can interpret them as they wish.
What? Why? Come on, this would be a huge loss for the forum! Are you going to continue posting here too?!