But Marius was only a General.

Though he became hot in Roman politics, audacious and confident, knowing how to use and how to disregard various weapons of political power as they had been handed down by tradition and law, the "vetoes" and the auguries, and the official dignities, he used them, or disregarded them, in quest only of power for himself.

He was able to perceive how vain was law in such a period as that in which he lived; and that, having risen by force of arms, he must by force of arms keep his place or lose his life.

With him, at least, there was no idea of Roman liberty, little probably of Roman glory, except so far as military glory and military power go together.
Sulla was a man endowed with a much keener insight into the political condition of the world around him.

To make a dash for power, as a dog might do, and keep it in his clutch as a dog would, was enough for Marius.