Yes, variety is always ideal. Crickets can be the staple, but if it is possible for you, try to add other types of feeders into your leos diet at least every now and then. Maybe add in some superworms...
Variety will keep the leo eating. If anyone just eats the same thing every day then they're bound to get tired of it and stop. Try mealworms, appropriately sized superworms, dubia roaches, and phoenix worms.