Ihtiandr, it would be interesting to see a Castle being taken not on its home territory and not by Valesk. Is it possible to do this without losses?

In the example, the Necropolis is taken not by Valesk, but by Caitlin, meaning by any hero. If you want to do this for the Castle, you need to do it for all castles, and there are two options - on Necropolis territory and on neutral territory. I think this is already excessive. Besides, by the time the Necropolis is taken on other maps, the troops are usually no longer the starting ones, so you have to improvise.

Ihtiandr, it would be interesting to see a Swamp taking the maximum Necropolis with 18 Lizards and 36 Gnolls, 1 Serpent, since it mainly gives such troops.

With such troops, it can be taken in a similar way, but more Gnolls will be lost. I explained the nuances in the battle description.