Bernardo wants to leave, and with Grealish at City he will basically get no game time at City, so will be easier to attract than Laporte. If Laporte wanted to come, that's a no brainer, but I doubt he will (especially as he can easily get back in first XI).
I disagree with you that it would leave holes in the team.
Bernardo can play in midfield, and is very hard working. I remember a couple of seasons ago he broke records in terms of distance covered for City in some big games. With his work rate, we can start Hojbjerg Bernardo Ndombele/GLC in mid.
Torres RW with £60M to fund Vlahovic leaves our attack very well balanced.
Defensive upgrades can hopefully be funded with sales of Sanchez, Dier, Winks, Aurier. £18M already in the bank from Foyth+ Toby. With not too much net spend we could bring in Romero, Lacroix, Aarons.