I sincerely hope that you are right DanA, but I worry a great deal about what will happen in the gaps between the goalkeeper and centre halves, the centre halves and the attacking fullbacks, and between the fullbacks and the 'controller,' or withdrawn midfielder - be that Can, Lucas or Allen.
I think the main concern is Mignolet. If our intention is to press high up the pitch - and it seems to be with the additions of Milner and Firmino - it means there will be loads of space behind the defence. It wont work without a sweeper keeper, and after a striker, it's our most pressing need. But there are no links to anyone as far as I'm aware. And it is hardly mentioned on here, when only 6-7 months ago, almost everyone thought we needed a new goalkeeper. What has happened since? Granted, Mignolet's form picked up massively after we switched to a back 3, but that reduced the gap in behind, and relieved him of much of the work with the ball that we ask him to do in a back 4. But now we are arguably going back to a four man defence again, and still have Mignolet in goal. It doesn't make sense to me.
And what about the central defence? Sakho is good, but hasn't yet established himself fully, mostly because of injuries, and he hasn't had a great partnership with Skrtel either. Skrtel isn't that great with the ball at feet, and has a tendency to drop too early. I think he does so to an extent because he's unsure of what Mignolet will do (who usually takes too long to make a decision), and all our defenders would be helped massively by a proactive keeper. But some of the problems will likely still exist, and with both fullbacks going on the attack this year, I expect plenty of 1 on 1 defending. Not Skrtel's best quality, and I dread to think what it will look like if Sakho is injured again this season. Lovren and Toure doesn't fill you with much confidence, to say the least.
Finally, there is the case of the midfield and how we'll line up. I think Lucas is an excellent player, but the lack of pace, and the gaps he'll have to cover is yet another worry. With Can, who is quicker, but lacks a bit of acceleration, and doesn't read the game as well as Lucas, the same is true. Sure, they'll be helped if we become a more aggressive side, but we wont win the ball every time we press. If we leave both our fullbacks and the other central midfielders high up the pitch, there will be much space to cover when our pressing fails. I think we should take such risks though, as it is how I want us to play, and Lucas or Can would do just fine if I were confident that we had the right central defence and goalkeeper. But as I'm not, the burden on whoever plays in the withdrawn midfield role is perhaps too big.
All that said, I still believe it will be better than last year, as we have added much needed energy and work rate. But the striker we sign should add to this as well (will Benteke? I'm not sure at all), and why I desperately wanted Tevez, despite knowing how unrealistic that was. A forward like that would obviously be great for our attack, but also help with the defending from the front aspect of our play. Is anyone similar available? I'd worry a lot less if we buy such a striker, and get a new goalkeeper as well.