I'd have Marshall at 12 and Strauss at 2. Simple as that really.
In my mind 13 is the big problem position in the squad. We seem to be producing lots of players who can play in the 10/12 channel, but very few for the outside role.
A look at the lineout success stats from the last 9 Irish games would suggest Strauss isn't a great deal more reliable...
Canada - Strauss - 93.3pc (Tuohy, Toner)
USA - Strauss - 60pc (McCarthy, Toner)
Italy - Best - 55.6pc (McCarthy, Ryan)
France - Best - 93.8pc (McCarthy, Ryan)
Scotland - Best - 76.5pc (O'Callaghan, Ryan)
England - Best - 83.3pc (McCarthy, Ryan)
Wales - Best - 81.8pc (McCarthy, Ryan)
Argentina - Strauss - 81.2pc (Ryan, McCarthy)
South Africa - Strauss - 80pc (Ryan, McCarthy)
One very good match each, one very bad match each, and a median of "Not really good enough but just about acceptable" for the rest. The real consistents here are the locks, not the hookers.