What are similarities between Sir Gawain of sirgawain and the green knight and Odysseus?

The men themselves are quite different, both in rank and personality, truthfully. Sir Gawain is actually considered one of the less able bodied men of King Arthur's knights, while Odysseus is probably the most able bodied man of his ship - of which he is captain, therefore making his rank notably higher than Sir Gawain's. Sir Gawain's quest is more that of a moral/ethical undertaking - will he follow the king's (green knight's) orders while he is away hunting, or will Gawain succumb to his base temptations? While, on the other hand, Odysseus' quest is of a much different nature, which is mostly to get home. Also, Sir Gawain quests alone, while Odysseus has a crew of men with him - though it dwindles over time. By the end, I'm not sure how much similarity there really is between the two, other than that they are both on quests (one by land, the other by sea).