Sasuke must have changed his mind again
Ok firdt of all hashirama meant by hiraisin was space time jutsu its not ftg.
It's possible that the events that occured last chapter happened while Hashirama had story time for everyone. Especially when Madara senses Hashi's chakra, he probably felt his chakra when Hashirama spiked his chakra to calm down Tobirama, at least that's what I think.
How do you know Tobirama's Hiraishin is instant? We know nothing about that teleportation jutsu
Not every scene in the manga plays out right after the other.
This chapter is showing what naruto and the others were doing as the kage were leaving the hideout
lol....it's just the plot being laid out right now.....be patient and wait.....Kishi will get there eventually