How do Trinitarians counter the argument that Jesus Christ is expressed as 'man' in Romans 5:15 and therefore is not (also) God?

The following has been quoted from a Biblical Unitarian Source >Contrary to the assumption that Christ must be God for redemption to be accomplished, we find, upon a closer scrutiny, that the opposite must be the case—that unless he was a man, Jesus could not have redeemed mankind. God’s “infinite” (we prefer a less mathematical and more biblical term like “immortal”) nature actually precluded Him from being our redeemer, because God cannot die. He therefore sent a man equipped for the task, one who could die for our sins and then be raised from the dead to vanquish death forever. This is the clear testimony of Scripture. >Romans 5:15 But the gift is not like the trespass. For if the many died by the trespass of the one MAN [Adam], how much more did God’s grace and the gift that came by the grace of the one MAN, Jesus Christ, overflow to the many! >If it were a major tenet of Christianity that redemption had to be accomplished by God Himself, then this section of Romans would have been the perfect place to say it. But just when Scripture could settle the argument once and for all, it says that redemption had to be accomplished by a man. The theological imaginings of “learned men” that only God could redeem mankind are rendered null and void by the clear voice of God Himself speaking through Scripture: a man had to do the job. Not just any man, but a sinless man, a man born of a virgin—THE MAN, Jesus, now The Man exalted to the position of “Lord” at God’s right hand. How would Trinitarians counter this argument ? ------------------------------------------------------------ >πολλω μαλλον η χαρις του θεου και η δωρεα εν χαριτι τη του ενος ανθρωπου ιησου χριστου εις τους πολλους επερισσευσεν [Romans 5:15 TR Stephanus, Beza, Elzevir and Scrivener all identical] ------------------------------