All castles in Heroes 3.

I play as Fortress...
but I don't understand one thing...
here's the development order:
1. Town Hall (1000 gold)
2. Guild of the 1st level
3. Market
4. Blacksmith
5. Magistrate (2000 gold)
6. Citadel
7. Castle
8. Capitol
and after that, developing troops becomes extremely easy, because there's money, and you can buy a lot with it.
With this order, I've won against almost all my friends, although there's a risk involved.
Tell me your opinion: what are the advantages and disadvantages?