Posts from War machines in Heroes V.
Do you have an account on Uplay? I haven't played in a while, but I won't let anyone disrespect mages... And as I already mentioned, there's a mass dispel to counter your mass slow.
And you said you don't see any problems... but I'm more than sure that things will go wrong.
I just pointed out the weak points in your arguments; too many factors need to align.
I often played with the upgraded catapult and learned to destroy both towers and the gate in the first and second turns... Even though I don't like summoning magic, this is more relevant to me. Although, for Necropolis, the direct path is summoning, but I rarely play with them. And I didn't say that in the first case, the mage will die, and in the second, he won't... it's just that the catapult is always available, and what you wrote: earthquake, hypnosis, etc., are already random factors (this is not the point, but I had a case in Heroes 3 where a fully built guild of mages with a library in Tower didn't give me a single offensive spell... since then, I've been wary of randomness 8)). A lot depends on the players here, but for me, during a long game, it was always difficult to storm the mages, because three archers and two flyers, supported by tough melee units and, of course, a pumped-up mage, make you sweat.
Regarding capturing castles in Heroes 5, with any race, a pumped-up hero, and a decent army, it's difficult to conquer and defend all of them, so I don't focus on castles; I defend my own, and the rest depend on the situation. In Heroes 4, it was generally easier to defeat an army in a castle than on the plains.
Added 1 minute ago
Yes, now I will capture the mage castle with particular interest.