RTF is a global modification that replaces all towns in the game.

Let's see what needs to be done:
Sanctuary:
1. Add effects to various animations (to hide their flaws)
2. Sea Elves
3. Giant Turtles
4. Rebalance.
5. Redo the second upgrade (on the Ice Nags).
Haven:
1. The existing creatures need to be "recolored":
downgrade - brown
upgrade - blue/brown
alt-upgrade - yellow
2. Arbalesters
3. Vestals (from Heroes 6)
4. In principle, you can take the Shining Ones from Heroes 6, but it's not necessary.
5. Unicorn Riders
6. City walls from Heroes 6
7. Hero
8. Rebalance

That's about it.