I don't think it's the worse trade in the world. Rios is having a lousy season. Adrian Gonzalez is having a great season.
Manny is Manny, but Gonzalez's season has been just as good.
So...breaking it down....Manny = Gonzalez....not bad Rios = Kemp also pretty much a wash this season. Harang vs. Lilly also isn't terrible. Remember you have to trade stats and not reputations. I would call this a decent trade and certainly not suspicious IMO Hope this helps.