I think it's beneficial to offer some alfalfa hay. Most pellets are alfalfa based, but anything powdered, chopped finely looses nutrients fast. My chins get some loose alfalfa hay daily, I think it's important to offer alfalfa hay at least 3 times a week.
I prefer loose hay because it gives chins the opportunity to engage in foraging behavior (I also mix some blossoms, herbs, roots) and coarse, fibrous stalks wear down teeth properly. Quality loose alfalfa hay, rose hips and some herbs are crucial to prevent dental problems. Alfalfa is a broad spectrum nutritive herb, excellent source of vitamins, minerals, even contains natural fluoride, flavonoids, every essential animo acid, numerous digestive enzymes and co-enzymes.
I also offer several grass hays, mostly for teeth wear, various textures wear teeth differently. Some alfalfa hay is actually higher in fiber than timothy. Timothy hay is a low nutrient dense forage, so chins consume a lot trying to meet the nutrient requirements, it's good for dental health and for the digestive system.