"An Army" implies that these are well trained, battle hardened, elite, tactical mice. In that regard, what type of headstone would you like on your memorial, seeing that there won't be enough of you left for a grave?
An army of mice sounds like a genetically modified group of mice, seemingly at least strong enough to break away from the science lab securities. So no, you wouldn’t stand a chance.
Your average mouse is less than 30 grams. 200 would add up to 6kg or roughly 13lbs.
That'd be like an elephant taking on 200 chiuauas.
If that seems worthy of a flex to you, you have my pity.