I give it a 10. Not because it's impossible (like holding all belts online at once in Fight Night), but just for the amount of time and prep it would take to get a platinum. It makes other time consuming games look easy.
Battle trophies are so incredibly random with things like "hit for x amount of damage".
Good luck to anyone who can put up with the game for the hundreds of hours it would take to get the platinum.
"The future is uncertain and the end is always near" - Jim Morrison