Fair enough, Maguire and Dier are good footballers but just not who I'd opt for as cover for our system. I foresee a mess if there's any issues, it's likely it would have been the same with Sanchez around too. It wouldn't have hurt to have another decent CB around but maybe that's asking too much.
It's for a different thread but it's the same for the left side, Davies doesn't have the same kind of recovery pace as VDV and still hasn't played as a CB pairing in the PL, doing it for Wales or as a back 3 for Conte is different thing.
We have taken a risk, you can do the pros/cons, you could say Philips is a better backup (worse case he learns/gets experience even if he fudges up, vs. Dier/Sanchez/etc. who have had years for same results) or you could say not.
We will punt Dier at next window or end of year, another CB or two will have to come in.