[Sombre]

Well they would be presented as variant nations as much as earlier or later versions of the nations.

For Lizardmen it could work this way:

EA - You are clearly going to have more Slann - 5th, 4th and 3rd gen all buildable, but no Skink cavalry, shamans, priests of sotek, sotek summons, red crested skinks, skink archers. Spawning summons all cheaper/more numerous. Skink Priests cost more and don't auto communion - are far less needed with Slann being a lot more common. Salamanders haven't been tamed yet - big dinosaurs are cheaper though, as are kroxigor. It's incredibly powerful magically.

LA - Sotek stuff and skinks rise more into power and sotek saurus and priests are now sacred - far less saurus, only 5th gen slann available at great expense, no more oldblood saurus and saurus scar veterans are expensive. Sacred spawnings cost more as do temple guard etc. Basically everything is more centered on skink and Sotek, with the crazy power of the slann being far harder to get to and more costly. You don't get 2nd gen at all any more and 3rd gen are extremely expensive summons. The nation is actually almost a blood one at this point.