I agree with the risk that there could be mistranslation, so that has to be balanced with the need for speed of communication. If you're in battle conditions, waiting for the translator to hear the message and then translate could lose valuable time. I'd also argue this could be a narrower use case where the militaries could decide on a set of common phrases to be used in such situations, which would be a much easier problem to tackle. So, yeah there are definitely pros and cons, but if translation can be made reliable then I can see a lot of benefits at least in some contexts.