The question of Saul comes up every-so-often in our church, usually in discussions about God's sovereignty, plans, etc.
There are some back-story things to consider about Israel and an earthly king. We have to remember that God always planned, at some point, to have Israel have a king.
The scepter shall not depart from Judah,
nor the ruler's staff from between his feet,
until tribute comes to him;
and to him shall be the obedience of the peoples.
(Genesis 49:10 ESV)
“When you come to the land that the LORD your God is giving you, and you possess it and dwell in it and then say, ‘I will set a king over me, like all the nations that are around me,’ [15] you may indeed set a king over you whom the LORD your God will choose. One from among your brothers you shall set as king over you. You may not put a foreigner over you, who is not your brother. (Deuteronomy 17:14-15 ESV)
So, the issue here is not wanting an earthly king. The issue is wanting a "king like other nations." This is best understood as wanting a king "that looks like and acts like the kings of the other nations." And, indeed, that was Saul.
Saul was tall, good to look at, etc., just like the other "pretty" kings of the other nations.
But, we should know from the text, the first time we meet Saul, that he was to be a bad king. Why? The first time we see Saul (1 Sam 9), he is on a mission to find his father's lost donkeys. The first time we see David...he's away from the family faithfully tending to his father's sheep.
The text implies who will be successful as king and who will be a failure.
Furthermore, we should have expected Saul to fail as a king--as he was from Benjamin, not Judah.
What is more, when Saul is dis-qualified from being king (which is to say that his offspring will not be king), it comes on the heals of horrendous disobedience.
One thing Saul does is to act in the place of a priest. Remember...Saul is already a King, he has already prophesied, and now, in the absence of Samuel, he sacrifices animals in place of a priest. Nowhere in Scripture do we see one man take the tripartite mantle of "Prophet, Priest, and King" until Christ.
Every king-like leader in Israel, Moses, Saul, David, etc., has, at most, two of the offices. Moses is a "King" and a prophet, but his brother Aaron is the priest.
I maintain that Saul is disqualified precisely because his disobedience--at its root-- is to appoint himself as "Priest" in addition to his kingship and his prophecy. Only Christ is allowed to wear the three titles and hold the three offices.
So...could he have done otherwise? Sure. He was willfully disobedient. But, knowing what the text says and shows through implication, we should have expected Saul to fail. While his disobedience was his alone, we should have expected it.
Blessings,
The Archangel