Would this be acceptable – or theft?

I have just read Ted Hughes’ poem “Chaucer” from the volume ‘Birthday Letters’, a vast collection of pieces written for / about Sylvia Plath.

The thing that struck me about “Chaucer” – indeed as it has about many of the poems I have thus far read in the book – is that they read like drafts rather than finished pieces. Is that sacrilege? In any event, it occurred to me that one could edit the poem to create something tighter, leaner, more impactful. Not necessarily better. Obviously.

Now. Is that acceptable? And if not, is it because it’s Hughes?

Chaucer

Swaying at the stile’s top, arms raised,

you declaimed Chaucer to a field of cows,

to the Spring sky with its laundry of clouds,

the new emerald of the thorns,

your voice over the fields

to become lost somewhere else.

The cows watched. Appreciating, approached,

you wrapt in the Wife of Bath.

Making a ring, they shoved and jostled

to gaze into your face, snorts of exclamation

renewed their astounded attention,

catching inflection, remaining six feet distant.

Disbelieving, you could not stop

fearing attack, the potential shock of silence.

So you went on, you and they hypnotised

until they reeled away

while my own commitment

was already become perpetual.

Mine or his? Acceptable or not? And if acceptable, how few words need to be changed to make it mine not his?

I don’t have an answer. Obviously.