Why would you use an FPS game engine from 2008 instead of developing a next gen engine specifically for sports games?
Every EA Sports title created on this engine have been some of the worst reviewed games to ever release. They make money but that's from gambling addictions and taking advantage of sports fans.
A majority of the problems not only this dev team but all the other sports games are facing would probably be solved by just starting over from scratch.
Scrap the open world idea, do what you can for FC27's gameplay and focus what you can on creating a new EA sports game engine. Not Dice's bad company 2 engine.