I say Sasuke beats Tsunade = matchup excuse
I say Sasuke pushed Itachi = matchup excuse
I ask you to list out characters Sasuke and Tsunade can beat = "don't want to because I know I'll prove your point"
How does this pass as an argument? Literally anything Hebi Sasuke does would be a matchup excuse, Its funny if I bring up Deidara who low diffs Tsunade you'll bring a matchup excuse again, and then to validate Deidara in a tier ranking the person Deidara beat (Gaara) who low diffs Tsunade would be a matcup excuse too.
When almost every other character is a "bad matchup" its not a bad matchup anymore, it means something is clearly wrong with the character you're defending
Also there is more to being a ninja than combat skills, Tsunade is exceptional in the medical field which is extremely useful in battle, that alone puts her at Kage level.
Except the bulk of your argument ignores fundamental things that are considered in the Naruto world such as how abilities compare to others. The examples you provided such as Orochimaru defeating Jiraiya, Hebi Sasuke competing at a high level with Itachi, and even Hebi Sasuke being capable of defeating Tsunade hinges of the idea that each of these fighters were well-suited in combating the opposition:
1. It's common knowledge that Orochimaru has the advantage through the Three Way Deadlock where Jiraiya could never defeat Orochimaru because of the Snake's advantages over Toads.
2. I addressed this and you haven't provided a feasible rebuttal to suggest otherwise. Orochimaru operated horribly in response to Itachi because he didn't have viable counters for majority of Itachi's techniques and a lot of Itachi's combat style incorporates Genjutsu. This is something Orochimaru could not counter because that was visually depicted whereas Sasuke could because he possessed a 3T Sharingan and was one of the only individuals who could conquer Tsukiyomi aside from Obito during that time period, but this is something you deliberately ignore.
3. I don't even agree with the notion that Tsunade can't even defeat Hebi Sasuke, but I will entertain it regardless. Sharingan is one of the most effective counters for those who prioritize on CQC and Tsunade's Taijutsu is hindered through Sharingan Genjutsu. The only way a close-range fighting style would effectively defeat a Sharingan user is if you're Raikage, Minato, or Gai.
Reason why I'm not using the same level of argumentation you are because Tsunade's ability to battle opponents in comparison to Hebi Sasuke is according to our subjectivity. Now, if you want to argue that Tsunade loses to both Sannin and can't defeat majority of opponents below the Sannin Level, then she is not Sannin Level. This is the logic you're applying and I'm not sure how you can push your agenda using that level of logic and have me believe that she still remains Sannin Level. If you're going to nerf Tsunade and conveniently push her to Sannin Level just for the sake of this argument, then I won't entertain this debate any further.
I disagree with the last statement because countless times are her combat abilities emphasized throughout the manga and the most notable ones were Jiraiya's statement about how no one could rival her in the battle-field or her introduction to Byakugou which enabled her to effectively engage in close-combat with Madara's Susano'o.
