Arcade competitor trophy appears to be impossible to get now because no one seems to be playing the featured maps on pc. I am an achievement hunter and got to this game late and now am seemingly unable to get this achievement. Why would you do this to us?
Don't bother. Play the multiplayer for fun and win, and you will get it naturally as long as you avoid playing Arcade Hero. Don't treat achievements as some sort of checklist you need to complete, otherwise you're not having any fun when it comes to Far Cry Arcade. Any Ubisoft map is featured, so keep that in mind.