I guess it's sort of necessary because of how many injuries our CBs pick up. Ake and Stones are pretty injury prone and Laporte is no stranger to a lengthy layoff either.
Then you've got to factor in that Ake would have been off to Chelsea this summer if they didn't pull the plug on the deal. I think it's fair enough for us to start planning without him or anyone else who might want to leave.
And I agree about having an academy player as fifth choice but, in all likelihood, in the event of an injury crisis Pep would just play a senior player out of position to cover there like he has done in the past.
This deal makes sense purely because of the low fee. As much as I love out of the blue signings, I'm not particularly excited about Akanji. He's got speed and a decent passing range but he's not got the aerial presence of Stones and he's about as far from Dias and Kompany in terms of last ditch, putting your body on the line defending as is possible.
If he develops under Pep to what he could have been a few seasons ago, we've got one of the bargains of the summer and even if he stays at the level he's at then we've got a decent squad option at a more than reasonable price.