You just have to "queue dodge" by going afk fo a bit so you don't verse them multiple times and coming back later. But basically, this is one major design flaw with the arenas. Blizz are working on a way to fix it with an "under the hood rating" but then there will be massive QQ about 2k+ rated teams taking a 30 point dive because of well geared teams that are playing with a 1500 team/personal rating.

But yea, just try going afk or doing something else then coming back later so you hopefully verse similar geared opponents.