Marriot was leaving to form Humble Pie thus the opening for Stewart/ Wood.
I think Rod is great on Truth, his first 2 solo LPs and Long Player.
The early Rod Stewart was great at phrasing. He had that ability to punch a word in the lyric that got the listener to focus and could elevate the content of the lyrics. Some critics compared him to Sinatra in that regard.
@bdp24 i agree with you on the greatness of steve marriott, who may be the best rock voice of the 60s/early 70s, but he was very obviously (if adeptly) aping his black influences. stewart, otoh, never struck me as especially derivative--if nothing else he had his own sound. which, of course, you may not like, but it is distinctive.
as for richard manuel, he was likewise incredible, but unlike others i never heard that much ray charles in his voice
I agree @loomisjohnson, I don’t directly hear Ray Charles in Richard Manuel’s voice. That’s a good thing! He internalized it, deep down inside, and it came out as his own voice. As did Van Morrison. By the way, Van and Richard trade lines in The Band’s "4% Pantomime" on their Cahoots album. Two great singers, a great band, and a good song. Who could ask for anything more! The depth of feeling and mutual admiration and love when Van sings "Oh Richard" and Richard sings "Belfast cowboy" brings me to tears.
I have to admit my opinion of Rod (and many "like" him) being influenced by my utter contempt for "Rock Star posturing". That’s was one reason I loved The Ramones showing up. Speaking of fashion: Did anyone else find it funny when all 4 Beatles suddenly had mustaches at the same time? What a coincidence. 😉