The leaves look too broad to be Cordyline australis.
It looks to be branching out at the base which Cordyline can do if damaged, but Cordyline starts to make a stem as it matures. Phormium increases by branching out at the base, there's many named varities which are dark ..
Hmmm, it does look to be reaching for the sky, I had trouble loading that so only checked the first one. Cordyline tend to have duller leaves than Phormium, could the plant be stretching towards light?