You shouldn't be the one extrapolating with 3 games. Maguire was an instant upgrade on the defence that season and helped get us back to the CL, pipping Leicester. Our defence record that season improved drastically. No debate on positive, measurable outcomes. Most fans were satisfied with the signing even if we knew the club overpaid. Even had Mourinho lamenting about the club not signing Maguire in his final year.
Back to Mount. The jury is still out to be fair, but not only has he been bang average whenever I've watched him, he's probably not what we need this season or even down the line.