Haven vs. Fortress (how to play against dwarves?!)

It's surprising how easily advice is given on how to counter the "late-game" Gnome. I wonder if the authors of these tips have actually tried their own recommendations in practice. Let's take, for example, the Dark spell – the Gnome can easily predict when the Knight will cast it, and then he equips "Antimagic," and all your Berserkers and summons become useless (and the Gnome will have more mana). And in general, in my opinion, delaying the inevitable won't save you, and increased training won't help either. I recently played a couple of games against a Gnome (the game ended around the 3rd week), and it was incredibly difficult to defeat him (and the hero wasn't even Ingvar).