Considering Claire's suggestion, Greg pauses for a brief moment to consider it...but decides against it. In hand-signs, he responds:
(Negative. Your specialty is stealth, from what I know, but mine's a little more...'direct.' If you want to help, keep an eye out for snipers.) Considering the given scenario, it'll be easier if Greg draws their attention, given that he's the one with better equipment for open combat, while Claire picks off any long-rangers (assuming that she actually has a sniper rifle or something, of course).
Then he hears Ghost's message, suppresses the urge to yelp out an "oh shit," and instead simply hides crouched behind a nearby tree, then sends a text message back:
Spoiler (click to show/hide):
This is Beowulf. Preparing to engage some targets of my own. Maintain radio silence. Beowulf out.
Seriously, they couldn't have timed that one much worse...here's hoping the enemy didn't pick up on that...