I think the midfield is very important, especially if we are to be a possession-dominant side like Rodgers wants us to be. I like Allen and Henderson a lot and think they are both very useful, but neither can do the defensive side particularly well. Lucas is good enough on his day, the problem is that his day only comes every 1 in 3 or 4 games now, and usually against the weaker teams. Lucas either needs to sort out his consistency or we need to bring in a specialty defensive mid.
If we want to be a possession dominant side then we do not need a specialist defensive mid. Whether Rodgers still sees us playing like this is another story because since January he's clearly altered our tactics and it's worked for the better of the team. Also, I'm not saying midfield is not important, I'm just saying that having matchwinners is more important because these are the players that win you matches. When he had a midfield of Gerrard, Alonso & Mascherano, which is as strong a midfield as you'll ever see, we still never won anything.
I agree with you on the point of being good enough for 80% of matches and ideally that would be enough but traditionally we've struggled against teams we should win against, often drawing or dominating and going on to lose. It's not been so prevalent under Rodgers but it's still a concern for me. I think with the top 4 being so close this year then any chance we have of making it has to involve beating a few of the other contenders. Picking up those proverbial 6 pointers.
However I think the midfield is the most crucial aspect of any team. You talk about having a defence and offence that should be enough but those two are linked together by the midfield. If you have a very open and defensively poor midfield then your defence struggles as a result. It's far more effective to defend as a team than to defend as individuals in the back four. Likewise with a solid midfield you boost your offence. Dominating possession and stringing passes around is far more effective for our team than last ditched defending and booting it up field to Sturridge (like we did against Villa away and United). Even for a counter attacking system you need midfielders to release accurate passes from deep.
My concern with the current system is that Suarez is bailing us out with his own individual brilliance. It's not to say that his goals are all solo efforts with no input from his teammates but take his goals against WBA for example. He scored one of the best headers you'll ever see, another brilliant goal and a third from a set piece. We were 3-0 up and gave up numerous chances to defend a nervy 3-2 lead with 15 to play. Not good enough and it's not the only time it's happened.
I agree with crosses that a simple solution would be to revert to a 4-1-4-1 when defending instead of the 442/4411 we use now. It will require more discipline and restrict the attacking potential of Suarez/Sturridge as they'd have to be shifted wide but it'd provide a lot more stability. Lucas has to drop into the holding role where he is better at reading the play and anticipating attacks. When in possession then the team can revert back to Suarez up front and Henderson out right with Lucas stepping up next to Gerrard.
Agree on the point that traditionally we've struggled against the weaker sides and raised our games for the big boys. However, under Rodgers the opposite has happened and that's mainly because he's focused less on the way other teams set up and trying to counter that, but rather on the way we as a team do with the ball. As a result we've done brilliantly against the weaker sides, hammered quite a few of them, but struggled against the stronger teams. I don't think it's the case of Suarez bailing us out, it's just that we've set up our team to allow Suarez to bail us out. And now with Sturridge in form, we have 2 matchwinners and these really come in handy against the lesser teams.
Also, I don't think our midfield is poor. It's a really good midfield, just not as good as Arsenal's. The reason I mention Arsenal, is because it was this game which brought about a massive reaction from fans that our midfield is weak. It isn't, it just isn't as good as theirs. And I'm okay with that because I feel we have better strikers. My biggest area of concern is the fullback area because Johnson is injury prone and our cover is not good enough there and at left back we need a proper starter there. To me, that's a more pressing issue than midfield.