tsunades revealed herself as the third strongest hokage IMO. she was compared to raikage in speed (if she was slower by a huge margin, why would madara bring it up?) and is possibly physically the strongest and most durable character besides third raikage.
katsuyu is an absolutely beast summon. division for defence, acid spit for offence and insane durability for her own.
Her behaviour provoked Nagato into destroying the leaf
she was defending her village's honor. nagato was the one who was gonna destroy it no matter what some random girl said to him
Besides, if you read the manga, there are several characters that speak highly of Hiruzen, even calling him the God of Shinobi.
and? that doesnt mean he magically has the means to injure tsunade
Tsunade isnt fast, everyone can dodge her. Even neji can beat the shit of her, just poke her and she is finished lmao
tsunade was compared to raikage. if she was a slowpoke jounin level, why would madara bother? hed just laugh at her. he clearly showed a bit of respect for her.