USMC 1st LT. Tyler Sanderson - Aaron Taylor-Johnson.

USMC CPL. Seth Rawlins - Will Rothaar.

USMC SSG. Joshua "Non-St. Petersburg" Martin - Gene Farber.

USMC CPL. Ethan Blackburn - Yuri Lowenthal.

US Army CPT. Allen - David Boat.

USMC Maj. Ryan Breckenridge - Robert Atkin Downes.

USN Adm. Mike Emerson - Matt Riedy.

Royal Army CPT. Grace Parker - Cornelia Hayes O'Herlihy.

Royal Army CPT. Owens - Craig Fairbrass.

Royal Marine Commando LT. Martin Cartwright - Peter Jessop.

USMC / US Army NPCs - Josh Hartnett, Joe Cappelletti, Troy Baker.

Royal Army / Royal Marine Commando / RAF NPCs - Gideon Emery, Kevin McKidd, David Alpay. 

(Grace Parker and Martin Cartwright are actually who I referenced for the original characters of the OG Game on the PS3, them being Stephen Cartwright and Rachel Parker, and I let them have the same VAs.)