Pulling Iwobi out of the bag at the last moment probably more than compensates for Lookman leaving. Having Kean in attack is a big plus. Sidibe should offer better cover for Coleman than Kenny did. Delph should offer experience, versatility and give us extra options in midfield.
They're the positives
We've signed Gbamin to replace Gueye. It's impossible to know how this will work out and whether we will be better or worse off for it. Given Gueye was probably one of our most important players, it's probably understandable to be slightly nervous about this.
That's probably a neutral one
The major negative is the centre of defence. We are left with a central partnership of Mina and Keane, neither of whom have any real pace and this could be an issue in itself. On top of that Mina had lots of injury issues last year. Once you get past those two, you have Holgate who has never really convinced, Gibson (who by Silva's own admission isn't ready for this level yet) and possibly the untested Gbamin playing there in an emergency.
That centre of defence worries me a lot and it's the glaring weakness.
There are more positives than there are negatives, but I think we are all going to have to cut Silva some slack if we have defensive issues between now and January because he's been let down pretty badly on this front.