He didn't say Tsunades regenative abilities surpassed Hashirama, he said their alike and or comparable.
Which they are by Madara's own dissertation.
Comparing Hashirama and Tsunade's healing is like comparing fire and water. While Tsunade might have healing that is compared to in the sense of regeneration, in the sense of actual debate -- Hashirama's healing properties are much more potent.
He's capable of accessing the same level of healing as the full Byakugou when activated, without it. Hence why Hashirama's healing via DB is stated to not be surpassed.
You call it wank yet you just proved my point, it said "his body was brimmed with vitality". You know what vitality is ? It's what's responsible for Hashirama's ability to heal, which as I already said Byakogou can do on the same level.
Hashirama's healing is what keeps Obito's MS from going blind therefore the Byakogou can do the same because it has the same healing feats as Hashirama.
Cell regeneration = no deterioration of the eye = no blindness
Byakugou doesn't grant vitality, what the **** :lol
The Byakugou has regenerative properties, but on the note of the actual discussion since you're going way off topic. You can't heal something that's being sealed away. Hashirama's DNA is a definitive property, like you said yourself. It's brimmed with vitality.
Hence why it could hold off the effects in the longer term. Probably.
Sealing mean not a seal in nature like Six Path Seal etc but it turned Uchiha eye into blind state after extensive usage. Think it like glucoma
Don't think that's how it works tbh. It's more like the eye sight itself is just being sealed away by the usage of the Sharingan.
