A nice article, but is clearly based on knowledge at this moment. I think the breaking point for the Sainz camp was the promotion of Max to the senior team instead of Carlos. And many unforeseen things have happened since. Who could have predicted at that moment that Daniel would leave the team or that Honda would be come the engine supplier of Red Bull. After last season most people expected that Pierre Gasly would be in competition with Max Verstappen at this moment.
In my opinion, and especially in Formula One more than 75% of a decision is based by hope and not more that 25% by knowledge. (and money of course....)
Cheers,
Huub