On prose style, British and American

I've started reading the Metaxas biography of Bonhoeffer because it was cheap on Kindle, I can read Kindle books on my phone and on my PC, and I thought it would be a ripping yarn and well-written.

So far I haven't got to any ripping yarn passages but I don't doubt for an instant that it's well-written.

And yet the prose style.

Well of course American authors don't read Fowler - how could ardent rebels read "The King's English" - but I should have thought they would read Hemingway ? How did UK and US ideas of prose style come to differ so widely ?

Here's a couple of examples (talking of Bonhoeffer's important family) -

"Their importance and influence may also be seen in the Michaelskirche (St. Michael's Church) where the Bonhöffers are marmoreally and otherwise memorialized in baroque and rococo sculptures and epitaphs."

marmoreally and otherwise memorialized - is it a tongue-twister competition ? an attempt to conceal the sense ? an exercise in alliterative poetry ?

And another :

"But the welter of wonderfulness that was their heritage seems to have been a boon, one that buoyed them up so that each child seems not only to have stood on the shoulders of giants but also to have danced on them."

welter of wonderfulness ? I looked up welter in the dictionary to try to decide in what sense it was being used here and I remain baffled.

And can one say wonderfulness ? Should one ? Why would one ? And what about beautifulness ? Would that be OK ?

Please don't read this as a criticism of Metaxas' style or of the book. Metaxas' style is impeccable and the book is wonderful.

But this welter of wonderfulness is in US prose-style and it's foreign to me and seems heavy, awkward, clumsy even.

To a British ear !
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