Upvote:0
History did show that Oda Nobunaga had contact with Europeans and even traded with them for prototype rifles. That being said, it was a possiblity he learnt somethings from the Europeans therefore he could have used what tactics the Europeans used on the battlefield and changed it as the situation required.
Upvote:2
It's probably fair to say that Nobunaga was the founder of the three line formation in Japan. That is, it's quite possible that he discovered it independently of European commanders. That's more plausible than to believe that the information "traveled" from Europe to Japan or vice versa, (given the communications of the time).
By 1575, arquebuses had been used in Europe for nearly a century, and sophisticated tactics had been developed half a century or more earlier.