This FanPost will attempt to answer a question that Romanisti have asked -- why is Mourinho so reluctant to substitute players on? Even if they're not ready, why does he not see what he has in 10-20 minute cameos? Why was the entire team practically rotated for the Bodo game?
I built this model by thinking through how Mourinho has acted at prior stops, and the nascent evidence of his time here. However, this analysis is entirely anecdotal. It makes some assumptions about how the rest of his time will go based on what Real Madrid, Chelsea 2, Manchester United, and Tottenham had happen, and I'm less confident in those, but I certainly think the nut of this is valid analysis.
When we as Roma fans call for subs to bring in players so they get some first team experience, we're missing the point. Mourinho isn't interested in creating a system where he subs in players to get looks for 20 minutes because even if in those players wouldn't have the chemistry that's so important to his systems working. Instead, Mourinho attempts to create two teams -- an A team and a B team, both of which have a lot of chemistry with the other members of that team.
He then wants to basically flip between the two teams (so play the B team during the ECL games, for instance -- that's why everyone was rotated out for the Bodo game, since they theoretically would have been training together). This would also explain why rotating in all the starters made the problem worse -- that chemistry was disrupted, since you had effectively two different chemistries fighting on the field.
The problem with this A team/B team dichotomy is the B team doesn't get enough play time to actually gel, and so they don't always play well. This sometimes creates a problem where the B team is playing poorly and then goes down one or multiple goals. At that point, Mourinho panics and goes to the A team. If the A team loses as well, then we see some of the Mourinho melting down. If the A team wins, Mourinho has pulled out the result. When the A team wins because they're actually playing regularly enough to build that chemistry or just through better talent, however, he doesn't see it as a virtue of letting teams play regularly, which would imply feeding the B team players into the A team setup in appropriate match situations. Rather, he uses it as proof that the A team is trustworthy and the B team isn't , and so starts using the A team more and more and more.
This has two key problems -- it both runs the A team into the ground and breeds resentment among members of the B team , until results dry up and the locker room turns on him.