Inferno tactics.

Demons and pits are still an effective combination. It's not always possible to build large armies and effectively sacrifice your own units, but with practice, you can achieve good results. Without demonology, you can't count on taking Utopias early.
A real game-changer in the first 1-2 weeks is the Expert Curse spell. Inferno has the highest chance of obtaining it – it can be found in the guild and heroes often learn it. If it's not in the guild, look for it in shrines, anywhere. It immediately reduces damage by 1.5 to 3 times (no joke – check it, read the spell description).

You're talking about taking Utopias in the first 1-2 weeks? Perhaps the minimum possible, with the appearance of Tazar in the tavern, a large number of free resources, a good starting location (and not just one), the fact that the Gogs are already built in the city at the very beginning, very good skills when leveling up, a large number of training sessions to convert soldiers into demons, and good luck. That is, 1-1.5 percent. Curse is a level 1 spell. Please explain how you take Utopias with Inferno on difficulty 4 using the 2Sm4d template, and I will consider you the most brilliant player for this city (I think not only I will).