When I first started teaching at my school I used whatever mallets were available. Later, as my instrumentarium grew, I began to cut down on the number of different styles of mallets I use. Yes, I realize that you get a different sound with a hard mallet as opposed to using a softer one, but at the level most of my classes play, I didn't find it necessary. I chose one style of mallet for my alto and soprano xylophones, a different style for my bass xylophones, another for my bass metalophones and another for my soprano and alto metalophones. My glockenspiels all got the the same glockenspiel mallet.
Now the students don't have any problems selecting the correct mallet for their instrument and life is much easier for me.
If your program needs three different type of mallets for each instrument, go for it.