Marco watched the others rush past, the familiar feeling of chaos washing over him. He closed his eyes and took a breath and focused, mentally cutting through all the chaos. He heard Strange shout and watched as peeked his head above the wall to see Wolverine heading towards Kael. He pulled open his yellow leather racing jacket and yanked three grenades from the bandoleer. "Hey!" He still didn't know her name, but it didn't matter at the moment, he'd gotten her attention. He tossed the inactive grenades to her, mouthing 'in case you need them'. The rest of the seventeen, he kept for himself. He didn't plan on using them while the tanks were close, but if they were pushed back for whatever reason, a grenade going off in Kael's face would likely distract him enough for them to get back into close range.
Then he gave Tink a signal and popped up above the wall, kneeling and bracing his rifle against the top of the wall to improve his accuracy. Without missing a beat he squeezed the trigger, opening up with short, controlled bursts, eyes narrow to dampen the effect of the muzzle flash. He made sure to keep his aim away from those in melee with Kael. Bet that stings worse than a blunderbuss.