I think the emphasis provided by using the pronoun explicitly would be closer to "And where are YOU fighting?", i.e. with an emphasis in voice which is not usually conveyed in writing.
But your sentence is also possible if you add some punctuation: "And you, where are you fighting?" or "And you? Where are you fighting?"
I put "And where are you all fighting?" as my answer and got marked wrong. I understand that English doesn’t always differentiate between "you" and "you guys" (or "y'all"/"you all") because often is just sounds a bit weird, but surely this is the correct way to translate from Hungarian where the difference is specified?