Why aren't there grouped levels to make it fair?

Why aren't there grouped levels to make it fair? I am on Level 3820 and work hard to place 1st or 2nd with my friends. Then a new friend or acquaintance joins in at Level 10 and within an hour wins 69 games and knocks me out of my place I have worked hard for. This does NOT seem fair at all. This has happened to me numerous times. I went to bed on Sunday night in 1st place and on Tuesday when the awards came in, I was in 2nd place and couldn't figure out why then I discovered an acquaintance had joined in and won 29 games over my number. There should be group levels with the difficulty of the levels.