Placement...issue?

Im sure were sick of placements. I just had a question...or comment. My friends and I played all 10 games of our placements in TT together. We went 6-4, all 3 of played the exact same games. However, after the placements all 3 of were placed into different rankings. How is that possible if we all won the exact same 6 games, and lost the exact same 4 games? Prior to playing we were all on the same 3's team with the same ranking and W/L ratios. Is it based in something else besides games won during placements?