While agreeing that many of the finest poets do have an immediately recognisable voice I think another type of poet has the right different voice for the
poem, rather than a voice we recognise first as the voice of the poet.
Familiarity with a poet will enable us to recognise a personal voice as well but it is not inevitably the first virtue.
After all, William McGonagall had a recognisable voice.
William McGonagall
Janet