Well at the very least 6 or 7 arena matches should be enough to generally prove there is an issue. All but one of the matches resulted in a Klingon win.
I randomly asked a few of the fed players if they won much and the general response was that the Klingons were better due to game design. This speculation.
For one, there could have been a klingon premade team running while you were qing up. Secondly, the fed pugs you were with could have been of very low skill/experience. There are way more factors than game mechanics that can effect the outcome of pug matches.
I just have to say that I pvp whenever I get free time away from work/responsibilities and I q fed and klingon. Sometimes I pug sometimes I team up with buds. The results seem the same either faction to me.