Ballpoint definitely has better manpower, too, but what good are a hundred soldiers against... a tank, for instance?
Well, I managed to blow up a tank with an assault rifle on Planetside 2. And an airborne personnel carrier. Just saying, don't discount sheer madness...
Game physics. It's basically giving a three-dimensional object an armor rating, deciding how much "armor piercing" power the projectile weapon has (math can vary here) and then adding up how much physical punch is left. In Mass Effect it's possible to kill the largest enemies in the game with a pistol, the weakest weapon, simply because these gigantic enemies don't have any armor value. In real life, bullets ricochet off tanks pretty much 100% of the time.
Granted, DF is not real life.
Depends on what the soldiers have. I call them squishy because of their lack of numbers(sort of anyway) and more reliance on heavy machinery compared to the more infantry oriented Ballpoint.
Okay, here's a scenario. 10000 ancient Mesopotamian warriors versus 10 tanks and 100 soldiers with guns. OR - BETTER - a real life, historical version: The Spanish Conquistadors versus the Aztecs. The conquistadors only had what troops they could carry on their small fleet of ships, while the Aztecs had an entire empire. The Aztecs had every advantage - they knew the land, superior numbers, stealth, etc. However... the conquistadors had better equipment. They had guns, and actual armor. All the Aztecs had were obsidian swords, maces, and atlatl, and the conquistadors wiped them nearly completely from existence in their lust for gold.
Edit: Not saying Parasol could possibly do that to Ballpoint. Just saying that superior technology can equal superior manpower.