How authentic is too authentic?

I'm working on a contemporary/historical dual narrative novel right now.  That means it has two different stories: one set today and one from a long time ago.

The historical story line is based on the Old English epic Beowulf, a poem believed to have been written about 750 AD.

Beowulf is written in 6,359 verses. Each verse has two accented trochee syllables, a pause, and then the second hemistitch of two accented syllables.  There is no rhyme, and instead the Beowulf scop (bard) used allliteration, repeating consonant sounds.  

If none of that last paragraph meant anything to you, relax.  You're normal.  Not many people except English professors care about trochees or hemistitches.   Here's a brief example, which might help you understand.  It is Old English, which is barely recognizable to us, so I've included a translation as well.
God mid Geatum    Grendles daeda
(God amidst the Geats  Grendle's deeds)
wlanc Weders leod    word aefter spraec
(The proud Weder lord    Words after spoke)  Most of my novel is written in contemporary English prose.  However, I felt I needed to give the flavor of the original work, and so whenever Maenan, the scop (bard) in my story tells a tale around the campfire, I wrote it in alliterating troachaic half-lines:             When the world was new       whelped from the blue mother’s womb
            Beautiful to behold it was,    full of fulsome wonder 
            Heavy the herds on the plains   Bounteous the berries beneath the forest
My critique buddies hated Maenan's tales. I argued long and loud how important it was to include at least a bit of the original form, but they argued that it was difficult to read and hard to understand.  They were tempted to just jump over the sections written this way.  That finally got my attention.  I rewrote Maenan's stories this way:    When the blue mother gave birth to the earth
It was beautiful to behold, and full of wonder
Huge herds roamed the plains, berries filled the forest My rewritten stories were easier to understand, and that led to my critique buddies understanding why they were included and how Maenan's stories related to the larger story.  Success!

Sometimes it's good to sacrifice some authenticity for the sake of meaning.