I mean, why not to make the Blue wizards warlords or cult leaders of their own Saruman-like proto-states? It would even be in line with Tolkiens own ideas. In a letter published in 1958, Tolkien tells us that

"they went as emissaries to distant regions, East and South, far out of Númenorean range: missionaries to enemy-occupied lands, as it were. What success they had I do not know; but I fear that they failed, as Saruman did, though doubtless in different ways; and I suspect they were founders or beginners of secret cults and 'magic' traditions that outlasted the fall of Sauron."

Personally I developed a head cannon were Sauron needs to recover the One Ring not only to conquer the West, but also to face some sort of misterious rival in the distant East. Why not the Blue Wizards? There is also some Tolkien material that supports something like that.

in the Last Writings we're told that their names were in fact Morinehtar and Rómestámo's, and their "task was to circumvent Sauron: to bring help to the few tribes of Men that had rebelled from Melkor-worship, [and] to stir up rebellion...They must have had very great influence on the history of the Second Age and Third Age in weakening and disarraying the forces of East...who would both in the Second Age and Third Age otherwise have...outnumbered the West."

Maybe they could be leaders of federations of client states?

Anyway, I gave it a lot of thought and want to share with you guys. Know it would be a great change and not simple to implement.

Happy new year!