It really is a question as to how those two would have done had they been separated.
They would have managed just fine...Me and my brother have played street hockey since we were kids but you don't see us playing in the NHL, so obviously we can establish right off the get that how good the Sedins are is not solely dependant on them playing together as some might have us to believe. We can also look at the fact the Sedins have an ability to elevate the game of people who play around them, bad players or players who are not good have enough trouble elavating their own game, let alone their linemates. Obviously it can't just be due to chemistry.... They took Jason King from an AHL player to a top NHL rookie. They turned wade brookbank into a sniper for a game, they got alfredson most of his points in the ten games he played with them, Carter put up a career high in goals playing with the sedins after comming off the worst year of his career, Carter has subsequently bounced back down to what 10 goals in 50 games? Taylor Pyatt has been having a career year playing on and off with the sedin's. Needless to say that takes good players, who have more going for them than just their own chemistry between the two of them.
I might also add that we see chemistry around the league, their are players who play well with each other, better with each other, but they still bring a great skill set to the table.
I realise there are people out there who just plain don't like the sedins but that is no excuse to reduce the ability of these players solely to the fact they have been playing with each other for a long time.