Yeah double teaming someone probably is the cheapest and easiest trick in the game.
About players being attacked becuase of thier reputations tho: thats just par for the course. If you have won a lot of games that means you are more dangerous because you are more like to win the current one. I definitely target high profile players over low profile ones when the opportunity arises.
However, it should also be said that high profile players are probably the most resistant to double-teaming just because they generally have great diplomacy.