I would go further and say most civs should be nomadic at the start which is why I think we will have to wait for Civ7. I like what they did for Maori but they had to give them super swordsman to make them viable. I guess you could make a barb camp civ and have to capture a city. Better hope you have horses.
Humankind has announced a 'nomadic Neolithic start' for all Factions - you don't even choose a Faction until you start the Ancient Era somehow - but they haven't, so far, released any details on how the whole things will actually work.
Neolithic Era needs to be represented in some way in any case. We now know that there were numerous cities settled during the Pre-Metal Period, relatively long-distance trade, and a large percentage of the 'technologies' that Civ has always relegated to the Ancient Era are actually Neolithic: Agriculture, Animal Husbandry/Domestication, Pottery, Mining, Stone-Working, Calendar, Wine-Making, just to name a few - oh, and coastal Boating (not sails yet), because islands were settled complete with domestic animals up to cattle several thousands years before Bronze was first used.
And not only did Everybody start as 'nomadic', quite a number started cities, gave it up as a Bad Job, went back to nomadic hunter-gathering or herding, and then settled down again somewhere Else. That settle - move-resettle pattern applies to most of Europe, Anatolia, and possibly parts of China and India.
The Neolithic, in other words, could be quite a dynamic and interesting start to the game. Since so many of the cultures that started in that era never made it to the end of it intact, it could also be, apparently like Humankind, a 'Pre-Cv' Era in which you play without specific Historical Cultural attributes/Uniques until you reach the end of the Era intact and then, hopefully based on what you've accomplished so far and where you are, pick a Civilization to continue the game.
My preference would be to get a number of possible choices based on your situation at about 4000 BCE, End of the Neolithic. On an island with, say, Animal Domestication, Fishing, forest and hill/mountain terrain: get a choice of English, Scots, Irish, Welsh, or Japanese. On the edge of a desert with Agriculture, Animal Domestication, Pottery, and a river nearby, get a choice of Sumer, Egypt, Indus Valley ("Harappan"), Kush, etc. Among other things, that would keep you from trying to play England with a bunch of Naval Uniques from the middle of the Sahara . . .