Guess this depends on where you are, i.e. your climatic conditions.
Another factor would be what you would use the coppice for ? Willow is used for basket weaving. I haven’t come across any information which suggests that any Eucalyptus can be used for a similar purpose, though its not something I would rule out, Eucalyptus is very bendy.
Willow is used to make, furniture, small utility items such as bowls, but its most notable use is for making cricket bats, due to its high shock resistance.
There are at least seven hundred varieties of Eucalyptus ! and its timber is used for general constructional and the wood is considered to be rot resistant, something that can’t be said of Willow.
Anyway, so far as my small plot is concerned the main use will be as sustainable firewood, fuel for the stove.
Here in Ireland, Willow or Sailes grow wild and whereas in Scotland, most land in the highlands reverts to Birch scrubland, I’d say here in Ireland it would be Willows that would take over.
At the time of writing I haven’t burnt Willow; Birch is excellent firewood.