Shawn definitely had more of a talking ability than Bret but at the end of the point, the point of promos was always to build hype for matches and to progress the story and Bret's stories were always a lot more complex and hyped up then Shawn's (Shawn's reign actively turned people away) so I just think Bret never actually needed a lot of talking skill as he managed to make all his feuds feel amazing without them, by the time he needed it in 1997 he had a lot of it to show and cut some amazing promos.
I've no problem with Shawn's ring work or his promo work but I feel like his character work was kind of clunky and awkward? in mid 90s his face run failed all because the ***y boy character just isn't a face character, and then he randomly started heeling it up, and then he stopped heeling it up, and then he finally turned heel. I never really understood the kayfabe motivations and ideals of Shawn in 95 to 98, simply because he was turning randomly and his character lacked the nuance of the Hitman character. in 2000s, his character work was again awkward to me considering he completely stagnated and legit didn't change characters for 8 years.
as much as I rate Shawn, I don't really think his promo work advantage is enough to overcome Bret's advantage in ctowd connection and character work, you just can't match a character with years of slow development culminating in a heel turn via just turning heel in a promo in August of 1997, for example.