Quite an interesting idea. If we could get the best deal it would be for them to agree to buy Guehi at the end of the season - we take Chalobah for say 25mil at the beginning of the transfer window and then loan us Chilwell maybe with an option to buy for say 20 mil at the end of the season. This, they'd pay very little for Guehi and we would possibly sort something else for up front as we'd have actually spent next to nothing in reality - whilst sorting (maybe) our left back issue, for this season at least. Sounds unlikely though as we probably haven't noticed we need a left back and someone else to improve the attacking midfield or forward line.
What would annoy me is if we buy a goalie as I believe Whitworth or Goodman, or both, will be ready for us next season. With goalies you tend to find that they're a bit like strikers who score goals at any level. A good, dare I say excellent in our case, goalie in League One is going to be a decent goalie full stop. The job isn't much easier at lower levels - arguably tougher.