Tactics for the Stronghold.

You used to play as the Barbarians! :)

By the way, in my opinion, the rush tactic in the situation you described doesn't work.
Even if a Barbarian with 2 Ogres and, say, 9 Imps defeats a Rampart army, the losses will be catastrophic - losing one Ogre is not the same as losing, say, 10 Elves - it hurts, but it's bearable.
I believe that the main strength of the Fortress lies in quickly exploring the entire map, capturing as many castles and resources as possible. Only then does the Barbarian have a chance to win. The fact that the 7th-level town is built in the first week already says a lot... that is, by the time of the final battle, when the Barbarians have finally gathered all their troops, even buying slow and weak units, and go into the last battle, they will most likely have more troops than the Castle or Rampart.

And clearing the map of neutrals with just Ogres and Imps is very convenient - the battles take place with almost no losses.
In my opinion, you should focus on this.