its just an observation, but for me Finnan definately contributes more going forward when Gerrard plays on the right. I take your point about Pennant hugging the touchline leaving less space to overlap, and equally opponents probably fear gerrard more, but still , staying wide creates more space for the fullback to exploit in the inside right channel but finnan rarely makes those runs. Its a situation that time will resolve as finnan and pennant figure out each others games a little more.