diamond playing with silvers

You have just as much of a chance at being placed against them, if you do a full premade 5 with people around your rank then your chance to have "gods" on your team is much lower. You place too much credit in ranks.

Normals have their own mmr. A lot of high ranked players don't have great normal mmr. Hint: elo is about 50% grinding in a lot of cases. Of course there are some that can get there really fast but some players have played enough games for their 51% win rate to bring them to the top.