John Fredrick Parker
Donor
I think this would do it. However I don't know how long you can postpone the fall of Assyria, due to their overextension. However if we are to stop the Achaemenids and keep Assyria alive the best way is for instead of attacking Judea and Israel...
Really you just have to stop or effectively crush the Neo-Babylonian Revolt; Assyria certainly doesn't have to last indefinitely, just maybe another generation or two, long enough to stop their replacement regime being someone as stablizing as the Persians. That gives them plenty of time to crush a small kingdom like Judea, give them the same treatment as their northern neighbor.