The ministry of Elijah and Elisha sets the scene for the Lord's punishment of the Israelites through the ultimate conquest of Israel and the destruction of the so-called first temple, beginning with the conquest of the Northern kingdom by Assyrians and then Jerusalem by the Babylonians. And indeed Isaiah also plays a part in this role, hence the attention as well to the scriptures from Isaiah.
When looking at the scriptural references used in Mark, they are almost all either to the Elijah/Elisha narrative, to the works of Isaiah, or to other prophets talking about the destruction of the first temple. When we look at the story of the destruction of the first temple, the story really begins with Elijah, then moves to Elisha, and then to Isaiah. Isaiah is the one who ultimately predicts the destruction of the temple and that fall of Jerusalem to the Babylonians. This explains the prevalent use of Isaiah in the narrative.
So the whole narrative about Mark contains within it the subtext of the story of the destruction of the first temple. References to Elijah/Elisha and Isaiah are used to recast the circumstances that led to the destruction of the first temple in light of the destruction of the second.
In discussing the fall of Israel to the Assyrians 2 Kings states:
7 Now this came about because the sons of Israel had sinned against the Lord their God, who had brought them up from the land of Egypt from under the hand of Pharaoh, king of Egypt, and they had feared other gods 8 and walked in the customs of the nations whom the Lord had driven out before the sons of Israel, and in the customs of the kings of Israel which they had introduced. 9 The sons of Israel did things secretly which were not right against the Lord their God. Moreover, they built for themselves high places in all their towns, from watchtower to fortified city. 10 They set for themselves sacred pillars and Asherim on every high hill and under every green tree, 11 and there they burned incense on all the high places as the nations did which the Lord had carried away to exile before them; and they did evil things provoking the Lord. 12 They served idols, concerning which the Lord had said to them, “You shall not do this thing.” 13 Yet the Lord warned Israel and Judah through all His prophets and every seer, saying, “Turn from your evil ways and keep My commandments, My statutes according to all the law which I commanded your fathers, and which I sent to you through My servants the prophets.” 14 However, they did not listen, but stiffened their neck like their fathers, who did not believe in the Lord their God. 15 They rejected His statutes and His covenant which He made with their fathers and His warnings with which He warned them. And they followed vanity and became vain, and went after the nations which surrounded them, concerning which the Lord had commanded them not to do like them. 16 They forsook all the commandments of the Lord their God and made for themselves molten images, even two calves, and made an Asherah and worshiped all the host of heaven and served Baal. 17 Then they made their sons and their daughters pass through the fire, and practiced divination and enchantments, and sold themselves to do evil in the sight of the Lord, provoking Him. 18 So the Lord was very angry with Israel and removed them from His sight; none was left except the tribe of Judah.
19 Also Judah did not keep the commandments of the Lord their God, but walked in the customs which Israel had introduced. 20 The Lord rejected all the descendants of Israel and afflicted them and gave them into the hand of plunderers, until He had cast them out of His sight.
19 Also Judah did not keep the commandments of the Lord their God, but walked in the customs which Israel had introduced. 20 The Lord rejected all the descendants of Israel and afflicted them and gave them into the hand of plunderers, until He had cast them out of His sight.
This is essentially the theme of Mark.
All of this, again, is why I cannot go along with Marcus Vinzent in concluding the Marcion's Gospel was the first. It seems to me that this story, developed as a pesher on the story of the fall of the first temple, must be the origin of the Gospel narrative. It would seem to be exceedingly unlikely that "Mark" would be able to take a story developed without any of this in mind, and transform a story so thoroughly to this meaning useing scriptural references to passages that did not originate in a scriptural basis.
Alternatively, we would have to conclude that Marcion's Gospel actually looked more like Mark than Luke, which I think some have proposed. That I could possibly see, but it has to be that canonical Mark preserves the most faithful rendering of the earliest narrative.