Without changing the experience situation, the portal to the town will be inaccessible, and therefore, the main character will not have time to return to the town to repel the elf attack. It is not necessary to immediately give level 12; it is enough to return the experience to a normal rate, add some sundogs, various buffs (including those with resources - there are big problems with them), and maybe add some more troops (for example, 10-15 monks). Is it really necessary to destroy all three catapults in two months, or is it enough to destroy the nearest one?! And if possible, please provide more details about the prophet's quest.
Okay, I will adjust the coefficient.
It is enough to destroy two. Between them is an outpost (garrison).
The second screenshot shows his house. You need to visit it - he will give you a quest for a phoenix feather cloak. Bring it, and he will destroy all the catapults.