Every club will wait until the final stages to get some deals done (look at Pool and Thiago). The reason we went for van de Beek is probably the same reason - other clubs were circling. Otherwise, I'm guessing it's a wait until the final stages of the window to extract maximum value possible out of signings. Chelsea are an outlier in how they have got deals done this window (and theirs were straightforward - prices they could afford basis the previous two windows and few competitors).
Also, van de Beek was a priority. You are underestimating how gruelling this season will be - and a tired Bruno is of no use, considering he is our creative spark and one of the few who tries to pass it forward. Plus, van de Beek can substitute for either Pogba or Bruno, so he was sorely needed.
Other positions are definitely needed, and I am kinda worried over the whole Sancho scenario (or another RW, I dunno). Let's wait until the end of the window before writing it off. CB, I'm okay if we hold it off for another season. Despite being shaky, we did have the third best defence, I believe (and this is with the inexplicable DDG errors). Can atleast look to improve on it before going for replacements next season. A LB seems important, considering Shaw's injury record and a RW. 2 deals, lets see.
Also, squad players, it's not easy to sell them in the current climate. Let's see. Expecting atleast 2 of them to be sold this window, and many of the rest are out of contract next season, so meh.