Arena ranking sucks

Me and three friends played 10 games of breakout all together won 8 lost 2 i placed higher then them most of the time then for some reason i got placed in silver 3 while they got gold 5 and plat 2… wtf?

Yep its completely broken.

In breakout, i won 8 out of 10 games. With 110 kills, 33 deaths and 30 assists (around that) and got Gold 1.

I absolutely annihilated for the next 6 ranks til i reached platinum. Got to 360 kills and 110 deaths over 80 assists (around that).