Tobirama win, speedster opponenet should never ever attempt blitz on hiraishin user . Guy lose in cqc.
Giy not fast as v2 ei unless in eight gate. If guy try blitz, tobirama replicate exac what minato did to Ei. Kunai flick last minute and counter from blind area of opponenet. Tobirama have reflex to do just that, as we see juubito shunshin blitz. Guy not have speed of that same level, so tobirama react easier, slash guy from above.
Gai can be defeat as long as play smart. Never engage 7 gate, therfore no wreckage in taijutsu. Just like minato would never be to engage Ei in taijutsu. Always wait back and time counter with hiraishin.
Tajuu Kage bunshin tobirama to use. Tobirama make many dopple ganger. All run separate way. Not possible Gai to target them all. Tobirama use his shunshin to create distance. Gai open 7 gate and tobirama tire him by wasitng his time. Guy can never know whcih tobirama real. Hirudora wasted on clone = bad strategy, 1 hirudora will deplete Gai very fast. Asakujaku wide range but can only to cover one direction per time. So gai can not to target bunshin in other direction. Too many clone for Gai to chase down. Tobirama senju, so tajuu kage bunshin easy for him, Gai run out of stamina before Tobirama will.
Speed of gai calibre never to work on tobirama. Tobirama much smarter and intelligence, have better strategy. Defensive tactic always best for Gai.