There are no brilliant solutions. That's my point.

This king is good and wise. A rare bird indeed, as kings go.

He has achieved absolute power to do anything he wants, and apparently has used it only for good. But when he dies, he knows the good goes with him.

He apparently has absolute and total control of his kingdom, he can make things happen just by giving an order. But he also knows without him there will be chaos.

He has this wonderful tool, the Assembly, handed to him as if by magic, the one source of power in the kingdom he knows is relatively uncorrupted. And he can control it. But as you point out, it has value only as long as it is weak and he is strong.

He has the support of his people. And they are happy and loyal.

What are the chances of that all happening in the real world?

No. I don't have any brilliant solutions, either.

The king has got one thing going for him: he knows better than to trust the merchants, and for the same reason he can't afford to trust any other power center in the realm.