Marsupial People

OK. It was only a matter of time before this topic arose.
It's one of those annoying points I raise at the tail end of parties when everyone is in cloud cuckoo land and most people don't quite get it.
It's about Marsupials.

Marsupials are Mammals, but not Placental ones. They live in Australia and South America. Nowhere else.
They did once, but we Placentals have driven them into retreat over the Cenozoic Era.

One of the main differnces between Placentals and Marsupials is that almost all Marsupials carry their young in a pouch.

Kangaroos, Koala Bears, Opossums, etc.

Now here's the good bit.
After Marsupials had been swept away from the rest of the world, they carried on in Aus and South America, which was then an island.

And Marsupials have evolved in parallel to fill many niches their placental cousins filled.
For example, there are Marsuplial Mice who look exactly like normal mice, but with a pouch.
There is a Marsupial mole, which looks so like a normal mole that even an expert can only identify it as a Marsupial by checking for it's pouch.
There is a Marsupial cat (which isn't very catlike, but close enough).
Pointis, all these Marsupials are far closer related to eachother than their placental counterparts.
That's convergent evolution for you.
Even odder.
In 1935 the Marsupial Wolf went extince. Ansd that did look like a wolf.
In the fossil record we find a Mersupial Lion and a Marsupial Sabre Tooth tiger.

Is there no limit to this Marsupial Mimicry?

Yes, there is.
An obvious one.
And this is my point.

Had the flora in Australia in the Paleocene or early Eocene been right, could Marsupial lemurs have evolved?
Followed in succession by Marsupial Monkeys, Marsupial Apes, and then...