Tobirama does not have a chance. He can't use his water jutsus, ET, clones...etc
All what he can do is running around with his FTG, and even that is debatable since A almost got Minato who's faster than Tobirama and has better reactio.
Actually, even with both of his hands, I think A would win more times than not.
Tobirama has obviously been portrayed as the stronger Shinobi; in-fact in this instance we can see exactly how Ei performed against a Shinobi with similar skills to Tobirama, and it was not necessarily a good performance.
I disagree. I don't see how Tobirama is portrayed to be stronger when he lost to Kin & gin.
On the other hand, A was portrayed to be able to handle them, and he was going to deal with them as well.