The way to do this properly would have been to have full lines for Dodge and Chrysler, as they almost did when Fiat showed up in the first place, and tune properly for each brand - Chrysler would be comfort-tuned and more traditional in appearance, while Dodge would be sport-tuned. Really, it does work better with Plymouth in place, but still, it would work.
One problem was greed with wanting to really cash in on Jeep's reputation, which is now somewhat less than it used to be, to the point that three other companies are working on taking away the Wrangler's supremacy in its little world (which got a lot bigger). Jeep got a lot bigger.
Ram as a separate division made some sense, but there was no reason to make that public. I still don't buy the idea that Sergio was planning to sell Ram separately. I think it was exactly what he said, an organizational method that translated to the public when they freed up new VIN codes. He did make Mopar and SRT brands, too. It was the Fiat way.
I am disappointed in Tavares largely because he failed to do this. He had presided over it in Europe, with Opel (NOT Opal) brought into the fold as Dodge was brought into Chrysler: Opels were phased out in favor of disguised Peugeots. That's fine. Each car variant was optimized in sales across three brands appealing to different people. That is not a terrible way to work. Hyundai and Kia and Genesis manage it. Toyota/Lexus does it. Chevy-Buick-Cadillac does it. Dodge-Chrysler could have done it, too, with Jeep participating in some areas.
Instead... what a mess, and it's not going to get better as long as Fiat is in charge, which is as long as Elkann is involved.