No, that wont work. Iv downloaded a bunch of maps off other players. More than 25. And no trophy. I know a couple of people who downloaded around 30 and one guy who downloaded like 45. Still no trophy. Downloading maps off other players on ps3 wont work.
Need to download them directly from the map menu. BUT ITS NOT WORKING. Its down worldwide.
I sent a support ticket to Ubisoft. For everyone who wants the "Adventurer" trophy you need to take 10 minutes to sign up to their dumbass website and message them about this problem.
Its the only way they will realise the server is not working.