As a "team of the world cup" rather than a team anybody would actually pick for a match, Mitchell over Maxwell makes complete sense.Fair approach. I'm looking at something along these lines:
R Sharma
T Head
Q de Kock
V Kohli
R Ravindra
D Mitchell
R Jadeja
P Cummins (c) [or Madushanka w/ Sharma (c)]
J Bumrah
A Zampa
M Shami
On a similar basis though, I struggle to justify picking Cummins over a number of other players (including Madushanka), who took noticeably more wickets at a noticeably lower average. Even if he'd be just about my first name down on a current World XI.
I'm sure there's all sort of arguments about taking important wickets at important times etc. but I'd like to share the love around different players where I can (except de Kock for some reason, but I'm sure he'll get over it).