Start on "Hero".

Hello everyone, I've encountered a problem on the "hero" difficulty level while playing as the Academy. I first tried playing on a random map as the Fortress, but it took me weeks to win because I only got a lumber mill and a mine (and some gems, but people had already cleared that area, and I just took it; they basically gave it to me). Now I'm trying again as the Fortress, but on the maps built into the game, and it's a bit easier. I use magic to deal with neutral creatures, using gargoyles to harass them and spamming spells under the sign, but I have to spend the night in the city because I run out of mana. As a result, the start feels a bit slow. Maybe you can give me some advice?