I'm not going to kneejerk after the recent results, Koeman needs to earn his corn and sort this team out, we have signed some good players.
There are worrying signs at the way Koeman has started with selections and tactics, but let's give him a few months to sort it out, you can not expect to hit the ground running with so many new signings and the fixture list that we have, we could be a totally different outfit when we face City, Chelsea and Spurs in the return fixtures.
Allowing Lukau to leave without a suitable replacement is poor, but that is not just down to Koeman, infact he will have been well aware it was a priority for the board and Walsh to get a striker in.