Watford play a 3-1-4-2 formation with very attacking wing-backs. The key area of the pitch will be in the wide areas as a failure to correctly defend against those wing-backs will either make us too defensive or leave us too open. Dealing with wing-backs is not an easy thing, so few English teams play with a back three that alot of England based players will never have come up against it before.
There are, as I see it, two options open to Norwich. The first thing they could do is be really agressive when in possession of the ball and have their wide-players and full-backs try to force the wing-backs into their own half, transfrorming the 3-1-4-2 to a 5-3-2 and really hurting Watford offensively. This would also lead to plenty of 1-on-1 or, potentially, 2-on-1 chances in the wide areas, which wingers like Bennett, Redmond etc. will really enjoy. The other option is to only have the wide-midfielders track the wing-backs to a certain point when defending before letting the full-back take over. This would allow the wide-midfielders to adopt more agressive positions and open up the possibility of the counter attack. Both options have their drawbacks and it really comes down to whether you are aiming to have more or less possession than your opponents.
Watford's midfield is very strong, McGugan and Abdi are both excellent central midfielders, but Toszer is the man we must get to grips with. He dictates attacks in that deep-lying role and provides the ball to their very attacking central-midfielders, wing-backs and forwards.
Because of all the above, I would go with a 4-2-3-1 formation. The wide players are positioned aggressively to attack the space that the wing-backs vacate or to force them back. The two central-midfielders cancel out Watford's attacking midfielders whilst the man in the no. 10 role is able to put real pressure on Toszer so he can't dictate their attacks. Assuming everyone is fit, I'd go:
Ruddy
Martin Bennett Turner Garrido
Tettey Howson
E.Bennett Hoolahan Redmond
Lafferty.
