Holtby only ever gets brought on for the last 25 minutes or so, and I think he does really well in his role - but at that point in the game, you want a Lennon like figure who's going to change the game, which isn't what Holtby is. Gylfie could have been better but he has a knack for being in the right place at the right time for us, which is valuable! Behind Bale, though, I think the two other key players for us this year have been defender-cum-striker Vertonghen and Lloris, neither of whom were at the club before this season, so I think "the team" is moving in the right direction.
In fairness, I think Adebayor is a special case, given he's a massive wanker. I don't even know why he bothered playing so well when he was on loan - to get the contract, I guess, but it's not like City could have just sacked him. God knows. Defore is a bit of a Scott Parker figure - does surprisingly well given he's clearly not up to the task. I don't think we necessarily need a Suarez or a RVP - though obviously they'd be very welcome, sans arm biting - we just need a solid, dependable striker who can put away the easy balls. We have good enough midfielders that we don't need a Rooney (of old)/Messi character who can create goals out of no where.