I wasn't saying we "should" go for a 3 at the back from the start, if you read the following words wot I wrote it says why we probably shouldn't go down that route. It's not the idea that's regressive, it's not having the midfield for it anyway, much like in Conte times but that's one for another day. When (if but it looks likely) Alonso wins the Bundesliga with a back three it won't seem regressive, as it didn't when Conte won the premier league, but you need players that are good enough. City have often played a back 3, I could continue but I hope you get the point.
But yes there's not a desperate rush to get him in the team, I don't see anyone saying he "must play", not even his gobbrick agent so not sure who you're referring to. My point is the wry irony that now we've got suitable back up, the first choice pairing suddenly know how to stay fit and not get suspended. Even if we don't have to call on Radu this season I'm still very glad we were able to get him in because it was a glaring gap in terms of squad depth. It gives us a better chance of actually doing something next season, a shame we didn't give ourselves a chance of doing anything this season but hey ho.