Phrygian Mode: Is a Phrygian Scale of Chords Possible?

This time, constructing a Phrygian circular harmonic scale of chords looks somewhat more promising than the Dorian circular harmonic scales.

The three principal chords in the above example, Em, Am, and B7, are identical to the chords of the key of E minor. So at least it’s possible to establish tonality around the I chord.
If you consider C as the relative key, its three principal chords are identical to the chords of the key of C major.
If you consider G as the relative key, its three principal chords are identical to the chords of the key of G major.

But the Phrygian mode has an Achilles heel. As with the Dorian mode, it’s the dominant seventh chord—B7 in the above example.