Like all challenges it is true that not all challenges are made equal. Some require all play in order to be completed and some require players to play complete Madden 25 coins games against the CPU. If you're just beginning your journey in the game, it's the "Assemble Your Team Ultimate Trainer" challenges are a suitable place to start as they'll provide you with plenty of gold cards that will allow you to upgrade your team's performance. These are the best players but they'll certainly be better than the ones you already have and can be used as a good backup until you're ready to make more enhancements.
The two "NFL Epic" sets of challenges contain many challenges that you can complete quickly and will reward you with gold players who will hopefully be players in situations of need. It shouldn't take all the time to accumulate enough points to qualify for top Baker Mayfield and Deacon Jones cards that act as anchors for every side. In addition, you'll build an impressive collection of coins over the course of time which you're better off putting aside to save up until you're able to make use of them at auction houses (more on this later).).
In addition there are plenty of other worthy challenges to take on however be aware that certain of them are likely to will take longer to finish. For instance, the "Superstar" challenges such as the "Superstar" challenge, for example, may take a bit of time to complete up the required 145 star, but will result in an 89-90 NAT player in exchange for your efforts. If you're a huge fan of a particular group or team, then you might be interested in starting"Theme Builder. "Theme Builder" challenges which will provide you with top buy Madden nfl 25 coins players, if you are able to finish them all.