What medal range he should be in wasn't what he asked.
First, XP has nothing to do with anything.
It's all on how many medals you have.
It's loosely based on the Elo Rating, which in principal is a good thing. It stops a runaway leaderboard, people who start the game now, still have a shot at topping the medal table (except it's bugged and broken). If you attack somebody with a lot more medals you climb up faster and it drags them back down.
That's the good part. The implementation is complete merde.
1. There aren't enough players in the game so you get to see 'No Opponent Found' quite a bit, depending on time of day.
2. The matchmaking is also based on medals, a Grade-A blunder. The range appears to be your medals plus or minus 1000 with an plus/minus 1 Age, but as you only attempt to climb medals with Global, you're basically only seeing Global Age bases.
i.e. If you are at 1000 medals and go to attack, your opponents will be in a range of 200-2000 medals, 200 bods are worth 1 medal for a 5* win (even if they are L198), press 'Next' a lot to find a 2000 medal player and he'll be worth 39 medals for the 5* win.
At high levels, 3000+ it's complete luck whether you go any higher, the amount of 20+ medal wins available are extremely rare, mostly <10, but the second you log off, you'll lose 5-15 on average, with the odd -30.
It's unbalanced and unplayable, until it's fixed, this is Farmville with guns. Until you reach a max global age army, don't worry about medals, just raid, raid, raid for 4+ hours a day for 8 months until you get there.
I bet the next update is the next University Professor to upgrade, not any fix for the core game mechanics.