Still well ahead of “man’s man”. Well remembered, aldi!
Edit: The OED has an entry (under poet) for poet’s poet, but curiously, the first citation (neglecting a bracketed instance of “poet’s poetry") is reference to Lamb’s sobriquet for Spenser rather than a citation from Lamb himself: “1844 L. HUNT Imagination & Fancy 75 Spenser..has always been felt by his countrymen to be what Charles Lamb called him, the ‘Poet’s Poet’. He has had more idolatry and imitation from his brethren than all the rest put together.” One would think that it wouldn’t be that hard to turn up Lamb’s original use of the term, assuming this isn’t a “Play it again, Sam” situation.
Philosopher’s philosopher is stated to be formed after poet’s poet (and the first citation explicitly makes the parallel) and writer’s writer says “cf. poet’s poet”.