Rival seeds in 1 Samuel

I wonder whether there's a double pattern going on in 1 Samuel.

On the one hand, we have Samuel, the child of promise. He comes at a time when Israel is in eclipse; he comes to a (heretofore) barren mother, just as the patriarchs came (as well as Samson, and Jesus, after a fashion, as well). God's action, not man's, will bring his salvation. And things turn around, temporarily at least, as a result of Samuel's work.

But, ultimately, the natural children inherit office from the father, and decline begins again: Eli's sons, Samuel's sons, and David's sons (ultimately).

We learn that the kingdom cannot sustain itself without God's continuing intervention. We need a messiah to solve Adam's problem, but every naturally-generated messiah labors under Adam's problem, and so cannot ultimately rescue us.

So 1 Samuel teaches us to hope in God's promised messiah, but also teaches us that a worldly succession from father to son will not save us.

The only apparent solution to 1 Samuel's problem is a seemingly absurd one: We need someone who will not die (so we are not left to the failings of his earthly successors), and who also is immune to sin (so that he himself does not fail over time as well). How will God provide us with that sort of messiah?

So 1 Samuel teaches us to hope, yet also to look anxiously to God to solve the predicament of natural succession that 1 Samuel also identifies.