why does it never surprise me when man united get what seems to be the crusiest group of them all?

mon citeh, fly through the group of death!

btw can someone explain how the groups are picked? i would have thought it was seeded like the world cup. my calculations tell me city won the epl, madrid won la liga, dortmund won the bundesliga & ajax won the eredivise. doesn't seem overly seeded to me.