Hi there, I’m Jimbo Fort Smasha and I’m a Siege-Castles-aholic…
I have a few ideas… Not all my ideas are good ideas however.
Different troop types; cavalry for fast attack, archers for any infantry, spearman for bonus against cavalry, a battering ram which attacks building blocks etc… Just to add a paper-scissors-rock dynamic and chaos to troop engagements.
A boiling oil room for anti-infantry parties might be a nice touch.
Room types to benefit specific weapon types; a gunpowder magazine to improve cannons (which could exode spectacularly when hit), a mathematics lounge for catapults & trebuchets…
A summoners altar to have a steady flow of troops e.g. summons 1 mud golem per 10s to March into the field
A dragons nest because dragons and maybe put a unicorn in there somewhere too