Excellent. It sounds like you are doing very well with their diets.
All Ambystomids are gape limited predators, meaning they can eat anything that fits in their mouth. because of this, it is very easy to provide a balanced diet. Now, since one of yours is not too keen on worms, but likes crickets, I would suggest gutloading those crickets. Gutloading is surrounded by a bit of contreversy as to it's effectiveness, however myself and quite a few others swear by it.
Other live feeders you can try are:
Cockroaches (ones purchased as live food, not ones caught in your cousin's brother's former roomates bachelor pad....
)
I prefer lobster roaches thanks to the folks here on the forums...
Phoenix worms
Pillbugs, Sowbugs (from a non chemically treated area)
garden slugs (from a non chemically treated area)
Moths (I trim the wings with sharp scissors a bit to make it easier for terrestrial animals to get to them)
Cabbage worms (from chemical free gardens)
Silkworms (available online)
Cutworms (chemical free yards and gardens)
Cankerworms (chemical free yards and gardens)
Beetle grubs (chemical free yards and gardens0