Loomis, Jim Capaldi was a very fine drummer, very cognizant and respectful of the singer’s phrasing and dynamics, as well as the song's structure. Being a singer and songwriter himself, that’s not surprising, I suppose. Now that you mention Jim, perhaps it was he and not Winwood would enlisted the services of both Roger Hawkins and Jim Gordon for Traffic!
Grant Hart I’m not familiar enough with to have formed an opinion. From afar, he appeared to be just another punk drummer. Speaking of that, did you ever read what the great Tony Williams said upon hearing Marky Ramone? "Now THAT’S a great drummer" ! I don’t think he was being facetious, either.
Doug Clifford was adequate for the music of Credence, but was what I consider a "pedestrian" musician. No original ideas, no personality, not very interesting. I feel the same about Springsteen’s Max Weinberg. Call me a snob!
Since this thread was asking about solos, but has taken a detour (sorry ;-), there is one drummer who should be mentioned. He was a big band drummer, and they were expected to play, and were routinely called upon to do so, a solo at some point in a live show. Dave Tough was loved by the other musicians in the Benny Goodman, Tommy Dorsey, Woody Herman, and Artie Shaw bands in which he played, in spite of his limited abilities as a soloist. They loved how he made the band swing harder and better than did ANY of the great drum soloists, and how his accompaniment made each of them and the entire band sound better. The Rock ’n’ Roll equivalent would be Ringo Starr, who, though he couldn’t/can’t solo like Neil Peart, John Bonham, or Ginger Baker, was a great ensemble player, making the song itself sound as good as possible. Those are different talents, and rarely are both found in a single player.
Speaking of players of songs, here is just a small sampling from the over 18,000 (!) that Buddy Harman played drums on:
"Pretty Woman" by Roy Orbison
"Little Sister" by Elvis Presley
"Ring Of Fire" by Johnny Cash
"Crazy" by Patsy Cline
"King Of The Road" by Roger Miller
and a favorite of mine, "Stand By Your Man" by the great Tammy Wynette. So tasty! The drumming, I mean ;-).