Partly because the demo is limited to 2 teams and i can't tell whether the Season mode in FIFA allows for EPL + FA Cup + Champions League. Also, does FIFA allow for World Cup tournaments?
Its hard to do a world cup as the selection of international teams isn't that great, for instance compared to the 2014 world cup the following are missing in FIFA
Croatia, Japan, Costa Rica, Honduras, Nigeria, Bosnia, Iran, Ghana, South Korea, Algeria
And the following are Partially licensed teams (messed up kits you cant edit)
Cameroon, Chile, Colombia, Ivory Coast, Uruguay, Swiss, Portgual, Belgium, Russia
FIFA has some national teams which don't look like qualifying for a world cup ((China, Canada, India) so you could use these and you can also pad it out with the European teams it has (Ireland, Wales, Denmark). I still think it doesn't look that good. If you look at Euro 2016, some big teams that have nearly qualified for this are missing from FIFA (e.g. Iceland, Czechs, Slovakia/Ukraine) so you cant use them, and also there are only 3 Asian teams (Australia, China, India), most World Cups have 4 (e.g. last one Australia, Iran, S.Korea, Japan, WC2010 swap Iran or N.Korea) - China and India don't look likely to make it to the 2018 World Cup. It's a similar issue with CONCACAF, you have 2 good teams in FIFA 16 (Mexico and USA), but instead of the next 2 usual qualifiers (Costa Rica and Honduras) you have Canada (haven't been at a World Cup in generations). It's the same issue with the African teams, Algeria and Nigeria (who both made the knockouts and both were at the 2010 WC) are missing (as are Ghana) and instead there is only Egypt and South Africa.