I think the OP is being harsh here for reasons that have already been said - Alcaraz is pretty decent for a 4th defender (and those saying Duffy - would you really trust a back line of him and Stones together? Better to only have the one rookie at a time for me), Kone is a proven PL striker and nowadays you're lucky to get one of those for sub-£10m, Joel is a decent prospect and an upgrade on Mucha, and McCarthy is obviously the greatest midfielder to ever play football.
So although I think Roberto did pretty well for his first window at the club (before he was properly able to evaluate where we needed strengthening and the state of our scouting network etc), let's say hypothetically that Roberto has another window where he brings in another 3/4 players on perm deals (and another 2/3 loans) which are far less successful - I think that's what we may have to get used to. I'm not slagging off his transfer strategy, it's just that I think that if Martinez wants to bring in two or three times the number of players that
Moyes used to each summer, that we can't expect them all to work.
With
Moyes, we were used to only making purchases that were a) very good value (in the main, Bily aside) and b) pretty good players (again, a few exceptions but not many). But we would also complain that Moyes didn't make enough signings. I think the new reality is that we will be bringing in a higher number of players but that the average quality/value will drop - but also hopefully with there being a decent number of great finds a la McCarthy in there. We'll see, I guess