...when we don't have the ball, yes. That's actually one of the tactical points of 3-4-3.
I prefer the way AVB handles his system using a high line and the DM dropping between the CBs to form a back 3, rather than putting 9 men behind the ball ala Martinez and Dalglish.
It is important to note that Martinez has been very successful with 3-4-3 - his 8 loss streak with Wigan didn't use this system, while the season closing 7 wins from 9 did, which included 5 scalps among the top 8 clubs.
I guess the point I'm trying to make is that we need a manager who has a definite plan (that has been demonstrated to be successful by him), and I don't think that 5-4-1 is likely to be his plan. Dalglish and Hodgson had no plan. That makes Martinez probably a better pick in terms of the team's tactics than either of them. Whether he can take the pressure in the media and the scepticism from the players and fans in his stride remains to be seen.