Minato and Tobirama Swapping
I dont know if this thread has been made already but this is my opinion on what happened in 641 during the swap.
Minato and Tobirama exchanged markings when Naruto and sasuke had begin to attack.
As you can see here.
Where the confusion is coming is people have been saying it was Minato's original that lept infront of Sasuke and Naruto and that Kishi made a drawing mistake.
What I think is, it wasnt a mistake rather Minatos clone. And here is the possibility:
Minatos clone jumped infront of them distracting Obito, Naruto and Sasuke, at that same moment Tobirama had already used ftg to appear at the back of Obito but hadnt touched him yet.
Because Obito was distracted, it gave Tobiramas chance to touch Obito as seen here.
Minatos clone then summoned Tobirama since he can summon anythin with his marking on and at that same moment Tobirama also summoned the original. Thus Tobirama who is touching Obito came to the position of Minatos clone and the Original Minato appeared at the original position of Tobirama and Obito.
As you can see in the lower left part, Minato tries to withdraw the orbs of Obito so that he wouldnt be able to use them to block the attack, thats why you can see the orbs around original Minato as in here.
These are my thoughts though, at least we would understand what happend very well in the next chapter.
Share your ideas if you understood it better.