You may be missing the point moeee, I accept I may not be explaining myself too well. An analogy.

Backyard cricket;

We pick all the kids from the neighbourhood who usually play cricket so we can have a 'cricket team' and play a match against the kids in the next neighbourhood. We have a plan. however, one of our kids goes home unwell and is replaced by the dude down the road who doesn't really play cricket at all but prefers marbles. He takes an extradordinary catch to dismiss the opposition captain ..... We're onto something !! We immediately go looking for any others in the neighbourhood who play marbles. We give one of the poorer performing cricketers the flick (ie; that one bad run), and now we have a squad of mostly cricketers but several marble players.

What happened to our original plan?
Is our 'new' side (mostly cricketers but some marble players) going to perform better that if we had just stuck with cricketers?
How do we monitor this new side? - Do we go and get kids who play tennis exclusively and whack them in as well?
Could we monitor a side of just cricketers better and look for ways to improve?

If that don't do your head in moeee, then nothing will. Want another list ? lol