There must be a reason why Clovis spear points looked the same all across North America, up until the comet strike 12,800 ya. It is probably because they were a trade good, so that anything different would be less tradeable. After the comet strike and its continent-wide wildfires, evidently the trade network broke down, and local styles drifted, freed from conformity.

People often talk about a "Clovis culture", but it is unlikely that a single culture spanned the continent. What we know about is just the spear points.