peoples like french, english, russian formed in medieval times and have existed for around millenia even if they not always were "imperial".
"existed for around millenia"
Actually, all three examples you gave have "only" around one millenium of history (Charlemagne's empire wasn't 'France' etc) so if you would like to base civilisations on the lifetime length they would be far behind Egypt, India, China, Iran, Korea etc
did anybody heard of seljuks or khazars after their empires fell? they were assimilated into other cultures.
This argument is ridiculous because it hides an
assumption that french, english, russian people will never fell or be assimilated because apparently we live at the end of history By taking this argument to logical extremes one could argue that
no civilisation deserves to be in game as eventually all empires fall and all cultures change or are assimilated.
I'm pretty sure that by the year 4 000 AD one could say as well "did anybody heard of French after their empire fell? they were assimilated into Zentraedi Northern culture". By this time all their achievements would be vain -
and seljuks were persianized even before that. those buildings were created by persian architectors, not seljuk. and khazars havent built anything noteworthy. earthworks - ok, not impressive. craft, trade? everyone did that.
"And europeans were latinized even before that, they were based on greek-roman culture. Oh and they havent built anything noteworthy. Skryscrapers - ok, not impressive, we have structures 10 000 metres high. Science, conquests? Everyone did that. English don't deserve to be on the same list as Zentraedi - after all Zentraedi build 100x greater structures and still exist as a culture!"
My point is, you enter dangerous territory, because once we look from the perspective of dozens of thousands of years,
every human culture change, become assimilated, their achievements are "not impressive" from current technological point of view etc.
Also, if you are going to be strict about criteria of inclusion of civ series - only long-living civs, only famous and known civs, only civs with monumental architecture, only super exceptional civs, only civs which influenced their continent etc - then it will turn out we are left with less than a dozen of civs that "truly" qualify. That would be
boring. I prefer a game with 40 "medium" nations to the one which has only "grestest of greatest historian approved stricly measured most influential civilisations"... 10 of them because other were not good enough.
I don't like going extreme and including fictional (united Polynesia of civ5) civilisations, or societies which clearly didn't qualify as civilisation (often proposed Inuits, Aborigines etc) in a "CIVILIZATON" game but I ultimately don't care about some too criterias of inclusion based on unclear notions of historical significance. This is a game about various exotic, interesting, unique civilisations and great people of all parts of the world across the entire history, not G8 elite club of measuring what historical empires were most influential. I prefer to see big empires and civilisations here, as they tend to be the most interesting, but if there were smaller societies with some very distinctive/cool flavour/characteristics then why not let them in.