According to ravas explanation of the machlokes rebbi shouldnt require 60 separate minachos.
The way Rava explains(2q in the point by point) the machlokes -everyone holds you can mix chova and nedava the machlokes is based on R, Eliezer Ben yaakov but even if rebbi holds like R eliezer ben yaakov he shouldn't need to bring 60 ranging menachos he should only need two of 60 one containing one lug and the other containing 2 lug and make a tannai - if the nedava is 60 the mincha with one lug is chova and the mincha with 2 lug are 2 nedavos if neder is anything under 60 the mincha with 2 lug is a mixture of my chova and a nedava and the mincha with one lug is a second nedava rebbi Shouldn't require 60 ranging menachos
Yossi b, Monsey ny usa
But if, for the sake of argument, he had been mefaresh 18 esronim, how could he be yotzei, according to the above tnai, since he will not have brought any kli which contains 18 esronim of flour?! This is why one requires 60 ranging menachos to cover all possible amounts between 0 and 60.
KOL TUV
Dovid Bloom
Since the gemara says he can mix chova and nedava in the above case the kli with 60 issaron that comes with 2 lug he makes a tannai that 18 issaron and one lug of that is for his chova and 42 issaron and the other lug is a nedava (and the other kli with 60 issaron and one lug is a separate nedava)