Which castle can’t be taken by a Necropolis on day 111?

Review after one day of gameplay.
Two hidden spots for Nagas. Nagas are already being purchased at level 114.
In the second week, a powerful stack of 16 Naga units.

And if all of this is placed in a Stronghold, there will be 15 Nagas. So, is it worth having one Naga with high attack power in the first week? How many Goblins will be lost if all battles are fought without using the "greying" mechanic?