Prime Wlad had a bit more speed and snap than Lennox, so I can see him punching harder with single shots. Lennox was a lot more fluid and varied in his assault though, and more willing to go all out on an opponent if he sensed weakness, which tended to be more devastating IMO.
After teaming with Steward Lewis had the jab all day over Wlad imo. No comparison, though Wlad was of course a great fighter.
I'd say Wlad's jab was superior to Lennox's actually, maybe not raw power wise, but that's not really the main use of a jab. He was just a lot more consistent with it, and along with his clinch and great footwork formed the cornerstone of his ring generalship. Lennox was a lot more fluid and natural a fighter though, more able to turn things around when they went a bit south. Wlad either shut down or resorted to excessive clinching; hurting Lennox lit a fire up his ass.