TODAY'S NUGGET: What if There's No Character Arc (a la Jack Reacher)?

I'm extremely curious about the upcoming film, Jack Reacher, based on the book One Shot by Lee Child.

Child writes here about 3 problems why the character of Jack Reacher is troublesome for film:

1 - Reacher's physicality (6'5", 250 lbs.)

2 - "Reacher has no character arc"

3 - "Much of Reacher's appeal is inside his head"

Immediately, #2 made my hair stand on end.

Awhile ago, a writer argued endlessly with me that a character arc is unnecessary in a script.

I countered that it's near impossible to make an interesting story without it. 

I even blogged about its importance here.

I bought the belief in Hollywood that it could not be done.  (Secretly, I'd hoped it was possible, but I have never seen it.)

So how did Christopher McQuarrie (Oscar winner, writer of The Usual Suspects, Valkyrie) adapt this book?

I am dying to know, & will report back as soon as I can read the script.

Anyone have thoughts?