I like playing fluff battles with my group and I put assembled my Carno as Kroq Gar with the intention of fielding him one of these days. I just need to find the Lustria book, or any sort of battle he fought in. (Very familair with Dwarf lore - my main army - not so much with Lizard lore).
Hmmm, his most famous battle was a battle that he fought with his few surviving spawning brothers against Daemon hordes. The most appropriate fluffy scenario would be a Magnfiicent Seven Scenario.
Lizardmen defenders, you have to spend all of your points on Lords and Heroes.
Daemon Attackers (or any Force of Destruction attackers in a pinch) with a regular army.
Technically, you should only use Saurus characters but that is overly restrictive in my opinion
Extra terrain features would not be amiss.
This terrain set would be especially appropriate for generating features.
Ruined Lizardmen Temple City
2-Ordinary Hill
3-Mysterious Lake (1-3 Ordinary, 4 Boiling Flood, 5 Necrotic Ooze, 6 “River” of Light)
4-Steadfast Sanctum (1-3 Acropolis of Heroes, 4-6 Wizard Tower)
5-Mysterious Marsh (1 ordinary, 2-3 Khemrian Quicksand, 4 Earthblood Mere, 5-6 Mist-wreathed Swamp)
6-Obstacle (1-4 Wall, 5 Blessed Bulwark, 6 Blazing Barricade)
7-Building or Ruin
8-Mysterious Forest (1-2 Ordinary, 3 Venom Thicket, 4 Abyssal Wood, 5 Blood Forest, 6 Wildwood)
9-Mysterious River (1-4 ordinary, 5 Raging Torrent, 6 River of Light)
10-Magical Mystery (1-2 Magic Circle, 3-5 Arcane Ruins, 6 Wyrding Well)
11-Sinister Structure (1-2 Charnel Pit, 3-4 Haunted “Mansion”, Sinister Statue 5-6)
12-Makeshift Settlement (d3 buildings and d3 fences)