I think the welcome backs packs are a great idea too, as they "force" you to keep buying the game every year or else you lose the bonus. But with the Buy FIFA 18 Coins SBCs I mentioned they would also reward the players for actually spending hours playing the game, not just buying the game for X consecutive years. Of course the rewards would have to be really small and untradeable to not give you a big advantage over new players.
They usually do this in mmoak, with the rookie cards coming through. You can unlock a high rated card this year and know theres one in the bank for next year. They could do similar with transferred players, kinda like a free ones to watch card next year for a high rated squad around one of the players (IIRC thats what they do with rookies too )!
Madden has loads of promos, intriguing pack bundles, sets (SBCs for FIFA) with insane rewards sometimes) and an enjoyable "divisions" tier system. I can't think of any ways Madden is "far" behind FIFA, in the Ultimate Team aspect. What do you have in mind?
Ok, having a 90+ player reward is different from FIFA but the aspect of being able to easily build a competitive team stands the same. The difference is loads of promos and solo challenges in Madden pump out tons of special cards and the more there are, the easier they are to obtain.
Gameplay, madden is the cheesiest most cancer gameplay at high levels/competitive games which is completely unmatched by anything in FIFA. Also the amount of cards that become irrelevant real quick meanwhile people are still using multiple base gold cards in their FIFA teams. I don't think I've seen someone using a base card in Madden in months.