hey mardybum
Yeah, nah, maybe, it's a tough one
Obtus certainly are not native to WA (right?), have nothing to do with it, but they could have been introduced. The phyllodes have obtus tips, but don't seem to have the rough edges we're used to seeing (but hard to tell from the pics). These phyllodes also look extra thin, ie: not wide. The growth looks similar to obtus, but obtus tends to be less denser with fewer nodes than those you've got. Looks a little more like longi but that's equally unlikely. Keep an eye on them though especially around nov-dec, if they're flowering obtusi style you may just be in luck!