Servant or Master?

[Raynor]

He was clever enough without it to defeat the Numenoreans with guile and without an army

Actually he did have the ring, and used it to a great extent in their corruption:

Originally Posted by Letter #211

Sauron was first defeated by a 'miracle'... Though reduced to 'a spirit of hatred borne on a dark wind', I do not think one need boggle at this spirit carrying off the One Ring, upon which his power of dominating minds now largely depended.
...
Sauron was, of course, 'confounded' by the disaster, and diminished (having expended enormous energy in the corruption of Numenor).