I was in the same type of CL last season, two level 21 against two level 22 at group stage. I got 1W3L in the four matchs against level 22s. The other level 21 lost all of them...
If I was with the same levels I should have been in playoff without much trouble, tough luck blah...

Such unlucky CL draw can happen in all levels but at the higher level this happen more often. At the highest level it is inevitable.
Clean number of teams rarely happens. Somebody will have to be sacrificed to fill the empty spaces.

Most of the game is determined by luck and as such it is inherently unfair anyway.