Yeah, I figured it was a studio decision to retain familiar faces, but since those chaps had a relatively minor role I figured their loss would be minimally felt.
About the troops, though... I may be a little biased, but I would have sent some Rangers or Special Forces (the official name for "Green Berets"). I can accept some Marines
Also, you'll notice that there is a second or two of footage in the trailer that shows our AF guys posing with an Army M1A2 SEP tank; why not just have the actual Army? And experience? I may have been in the "soft-skills" / REMF category, but if I can hit man-sized targets at 300 m I can reliably hit a Decepticon a city block away