I agree with most of this, except for TenZ's impact. Some plays are very risky, but then again, he also provides some new looks for this lineup.
I don't recall a time where double OP looked as oppressive with sinatraa on the lineup. Shahzam has also seemed to reel back some of TenZ's "reddit/twitch play" tendencies and made him even more dangerous and unpredictable.
As a thought experiment, change all the Sentinel players to others with similar skill. If the IGL wasn't Shahzam, this whole thing wouldn't be a conversation. Shahz being able and willing to give up one of his signature picks (Jett), and play something else like Sova, is the reason why TenZ looks so good on this team.