the royal was a stretch, unlike your other examples Dave. Plenty of examples of similar approaches from most manufacturers. Mercedes immediately comes ot mind.
Here in the Antipodes,
Holden had very specific product specification hierarchy starting in the HQ series employing the same chassis except one.
The Belmont was the no frills base model sold as a fleet vehicle. It had the 173ci engine and three on the tree, bench vinyl seats and single speed wipers.
The Kingswood was your Dad's car. It ran the mighty 202ci red engine and probably had the tri-matic auto slung behind it. It still had bench seats but they had patterns in the vinyl! And an armrest! And 2-speed wipers! Lordie.
Your retired uncle and the guy down the road who had his own building business drove a Premier. Flash gits. Velour trim, electric windows, tinted screen, banded wheels and, just perhaps, the 253ci V8. Definitely a trimatic box. Faux wood trim in very odd places.
But if you saw a Statesman or (swoon) a Statesman Deville, you knew you were in the company of a CEO or local dignitary. On a lengthened chassis (well, the station wagon platform but that doesn't sound as dignified) and muscling a 308ci V8 in front of the venerable trimatic, this was bourgmobile motoring for the sunburnt country.
None of them would steer around a corner to save your life and the brakes were, well, exciting. Simple and happy times.