If we get at least one midfielder, another CB and a LB, then I will be more optimistic. Cautiously so since ETH also spent most of last season making weird decisions.
I can't see that happening though, and I'm not even sure the two signings we have made leave us any better off than before in the immediate term. Varane probably offered more than any 18 year old defender realistically could. Yoro might turn out to be a great long term signing but immediate term we need more experience. Zirkzee I will have to actually see him play to judge.
Midfielder I do think we can get away with one signing for the time being, but that's dependent on not losing what we have. Fullback...I mean we're going into the season with just Luke Shaw, who has been fit to start 1 game in 7 months, and then immediately been off for a month and missed the pre-season...what can possibly go wrong?
There's quite a few players, Shaw being one, where its not unrealistic to at least hope they'll offer more this season and make a positive impact, either through playing better or not being injured. Martinez, Rashford, Diallo, Sancho, Mount, Shaw...even Mainoo missed nearly half the last campaign. So there is that to base some optimism on.