I think it goes further back than the Sigurdsson deal, tbh.
We seem to have added three players who can all play in a similar role in: Rooney, Klaassen and Sigurdsson.
I would have focused on the striker deal early doors, along with Keane/Pickford, and then got them deals over the line.
Rooney(these days) and Siggy could be said to be quite similar, but Klaasen is different(allowing for him to get up to speed a bit)...Klaasen seems to be quick of thought(not feet,yet,if ever) and good at arriving in the box late to do damage. Rooney may well be our main striker at least until Christmas, dropping deeper in the last 25 minutes of games when he tires. Looking at the strikers available(hardly any top class...very hard to 'replace Lukaku' directly), a sharp,fit, Rooney for an hour might be our most effective choice.
Of the strikers who have moved this window, who do you think we should have gone for? There aren't many!