I don't get it. We said there are no external dwellings.
Where could 5 giants come from on the third week? I just can't understand. Count the turns—you aren't building giants in the Castle on the first day; there aren't enough days!
More likely, nagas were built in the Stronghold on the first (that's a good option). That makes 5 nagas by the second week. We build giants in the Castle on the second. This means on the third you get 9 nagas and 3 giants.
If there are external dwellings, that's a different story. If you took a giant external dwelling on the second—in that case, you'd actually have 6 giants on the third.
Taking the Dragon Utopia with golems on the third week is pure fantasy. I understand—scouting and all that—but look at how much damage golems do to dragons... Golems are brought along as meat, that's clear, but relying on them as a strike stack in the Dragon Utopia on the third week is doubtful. Djinns are too weak, and their numbers aren't impressive either. Skeletons—yes. Galtran definitely rules. Though, if you send him into a snowball, it'll be very funny. But that's already a question of turn management.
And plus, the respawn must allow for some skeletons to be scraped together.