Cimber said:But with this apporach you would get a much better Tour and Giro. Much more open for everyone
I don't see how you can draw that conclusion.
You are assuming that all the big names would be racing the Giro to win, when riding the first week or so could almost conveniently form part of a Tour training programme.
You simply cannot construct a contract that could guarantee this outcome.
So, we are left with some form of a gentleman's agreement.
The trust required from all sides, for that to happen, would be enormous.