The following calculations seem to distinguish between them. > #LowIndexSubgroups(GA,4); 30 > #LowIndexSubgroups(GB,4); 26 They have different numbers of homomorphisms onto $A_4$: > #Homomorphisms(GA,Alt(4),Sym(4)); 5 > #Homomorphisms(GB,Alt(4),Sym(4)); 1 (The options third argument $\mathsf{Sym(4)}$ means count (surjective homomorphisms) up to conjugacy in $\mathsf{Sym(4)}$.)