I don't get matchmaking

So I have been playing league ocassionaly for a few years with around 300 normal wins and this week I started ranked, placed in Silver IV. I just lost a game bringing my LP to 0 and it felt like some of my teammates were not the best. After we lost (hard) I checked player stats

Our team: 5 wins (me) 4 wins 17 wins 31 wins 12 wins

So all of us quite new to ranked play

Enemy team: 199 wins 407 wins 52 wins 541 wins 387 wins

How the hell does that work? I know MMR comes into play but this is obviously wtf-worthy. The enemy team seems fare more experienced, they also had more normal wins than all of my team.