I played milsim paintball before switching over to airsoft and I milsim paintball has evolved alot more than people think depending on where you play.
All our games had the honor system for hits just like airsoft because 90% of side arms were all airsoft pistols. We had medic rules, with scÚnarios based on gameplay and strategy, not seek and destory everything in sight.
We never did a game of airsoft vs paintball and honestly I wouldn't play in one. All the airsoft player would need fullface masks, your gear would get covered in paint that you need to clean up at the end of the day. The primary reason I switch over to airsoft was because I was tired of of spending 2 hours cleaning all the paint off my gear after a game.