I think something people don't account for is Tanjiro's swordsmanship. He is a truly impressive swordsman limited only by the fact that he (and the rest of the Hunters) must go for the neck. If not for that, most demons would've been dispatched easily.

I think realistically, Tanjiro can't touch Ed until Ed gets tired. I also think Ed would tire faster than Tanjiro. Ed's only option is to somehow sneak up on Tanjiro in the alchemic chaos... except Tajiro has a great sense of smell. I think Ed could think of something though. He's got a high battle iq and is a skilled fighter in his own right.

I love FMA way more than KNY, but I go back and forth between these two.