I think this is very realistic when you really look back on history. Two vast armies fighting it out. One army lined up with a sea of mighty war machines and the other hunkered up in a castle.
Each side having a ball throwing boulders and flaming oil on each other until someone cries 'timeout!'
Then one side builds more war machines while the other repairs the castle. It happened all the time! I swear! Really....really....
And of course those being seiged may not have food or water...but they have tons of construction materials. That is a given...duh!
-Christopher
