whitewash Cromwell, blackwash More?
Okay, I don't know the historical sources very well - admittedly.
And I don't know how closely Wolf Hall follows those sources.
However: just "scanning" More's career via Wiki, I think the series does him a disservice, even judging by Wiki's small amount of presented data.
First, the actor selected to play More: not just elderly, but sloppily and penuriously elderly - like an aged, scrawny, hook-nosed Scrooge - nothing like the Holbein portraiture. And a slob. In his first extended dialogue scene, More is tacky: his shirt has schmutz running down the middle - whether the filth is food spillage or a tear in the shirt that More is too oblivious of, or too cheap to repair, the clothing decision immediately pegs him as a Grubby One from the get-go.
In fact, all through the More-story I found myself wishing that Rylance had played More - "it's the eyebrows" - but not only the eyebrows. If they wanted to portray More darkly, Rylance could easily have handled the part as scripted. A Rylance/More - this I could believe as a torturer/capturer of heretics ... but also as the man who educated his wife and daughters in a time in which such treatment of women was exceptional...and as the man who wrote Utopia. The man who said at his execution, "I die the King's good servant - but God's first". Not only did the screenplay deny its More this final dignity, it denied him any prior credibility as "the Great Persuader" of his times. Simply having Cromwell mention that More is the Great Persuader is insufficient to establish More as such in the viewer's mind.
Second - and again, admittedly, having not much exposure to the historical sources - I have read enough and seen enough British documentaries to know that Cromwell was responsible for at least as much misery, imprisonment, torment and killing as was More. The series skips over Cromwell's darkness(es) - just as A Man for All Seasons ignores More's evils. Which is of course dramatically necessary in order to present a character ethical enough to encourage sympathy. But, having said that, I wish the script had been a bit more favorable to Thomas More.