After many restarts, I spawned in the underground, but with a bunch of Troglodytes.
On the first week, the native secondary town was on the surface, and at home there were only mines in the Castle; there were no resources for the Elves.
On the second week, another secondary town of Necropolis and building of the Castles. I took Lacus as a main hero, she leveled up really well :)
On the third week, the opponent brazenly captures the secondary from the rear, and a positional game ensued. I send Kyrre into the treasure zone I had scouted, Laca takes the level 2 Griffin Conservatory, teleports home, and captures the secondary, cutting Kyrre off from the chain and reinforcements.
We decided not to continue. Thanks for an interesting and dynamic game.