That’s what I mean the recollection of the Buddha started as something for the founder of Buddhism. There is not a special sutta where Buddha recommends to recollect all the Ancient Buddhas.
So either we have to believe that recollection he meant for all Buddhas or that the list of Buddhas is a later tradition. They didn’t think to make a sutta of recollecting Buddhas.
That means the idea of Hermit Buddhas seems to predate the ones of many Full Buddhas.
It seems it was about Hermit Buddhas at first.
It’s interesting that the recollection of Buddha is in AN. Because I think those seems early suttas.
And then in Khuddaka Nikāya has texts about hermit Buddhas. Like the avadanas.
And we have the tradition of the sutta of verses of hermit Buddhas.
And then there this in Petakopadesa
But that there is no recollection of the ancient full Buddhas. What indication that must be for us?
Vimuttimagga goes in detail of course in recollecting the deities. Meaning focus on various. But of Buddha it doesn’t seem for all.
Maybe the believe all is one?
But it can be that the many Buddhas came from a generation that was not in recollections.