The minimum tire size for EX721 is 2.3" and that limits the choice.
What tire and size do you use?
Bike Came with Continental Travel Contacts on it 559-47,
stayed with that when I fitted Schwalbe Marathon Plus.
want to run a narrower tire ?.. 1.5"? suppose you May want a narrower rim them ..
But, its only a 1/4" narrower ..
As far as Mavic goes, they have a product filter on that page say what tire you like and theres rim suggestions.
MTB rims | Mavic