The way they alter the future is not the same. Lucius is quite broken and impressive, but less haxy.
Lucius sees different futures, and then acts accordingly in the present to get the future he wants. In other words, he "sees the best path ahead of him knowing the results". Asta simply blocks his sight of said futures, making it so Lucius doesn't know what his best action is anymore.
Yhwach, on the other hand, by his own admission, has the power to "choose a future" and it happens without causation. Like for breaking Ichigo's bankai: Yhwach just had to "shift Zangetsu to a future in which it was shattered".
Lucius isn't weak at all, don't get me wrong, but if I have to vote between two characters with powers like these two, I vote for the one with the better hax. The hax that grants more invincibility.