This is a very strange deal.
Let's say he plays well for Wolves for the year and they activate the 5m. Okay fine, they will see a good-ish player for 5m as amazing value, we will see that as them underpaying but hoping they sell him on.
Year 2, Doyle improves even more, but what is his ceiling? Maybe he turns into a player where another club comes in for like 60m, that would mean he massively improved into a good player.
But then Wolves look at that deal and say, wait we only get 30m from that, and City get 30m, doesn't it make more sense for us to keep him? Why get 30m for a 60m player, doesn't make sense for them.
Whatever value he rises too, at 50%, it just makes more sense for Wolves to keep the player in any scenario.
So a very strange deal imo.