Not necessarily, any UK Mercedes with CIS after 1984 generally has twin pumps. Some models had it earlier, some later, although it could be a USA vs UK market difference.
I do envy the climate you guys have the other side of the pond, I have friends in Arizona who are shocked at how bad some UK cars get underneath.
For example? I'd be interested to know as I've owned several non US spec cars (4, 6 and V8) and none had twin pumps.
A friend of mine has a E300TD Wagon (OM603 turbo) that he mated a 722.6 5 speed automatic. It pretty much transformed the way the car rove. He also had an E300D with an OM606. For a diesel, it revs. It's not turbo fast, but I wouldn't call it slow.