@mijostyn lets say we have two wide band speakers.
And we time align them in the 10-20kHz region.
One has a 12dB/octave HPF slope at 2.5 kHz.
The other has a 24 dB/octave slope also at 2.5 kHz.
The phase between those two will look different in the DC to ~5kHz region.
Then lets say we have time aligned a woofer and sub at 120 Hz.
The sub is in a bandpass box, and the woofer in a sealed.
as the frequency goes towards DC the two will deviate in phase from each other.
We could address both of the phase in the first case, and the group delay in the second case with a DSP to correct the phase, or at least in the tweeter case, some XO magic can be done to better align them in phase in the ~2.5 kHz region. (I cannot do it in solder, but many can).
Usually the time alignment is done, in a “minimum phase” sense… and it is done somewhere where the phase is not swinging wildly from say, group delay.
So they are tied at the elbow, but they’re distinctly different once we talk about more than a single frequency. At any given frequency they are effectively able to give the same correction.