You have had these two GTFs for two and a half years and they're only 1 1/2" long? Either you're not measuring right, there is something wrong with the frogs, or you don't have GTFs at all. Is there any way you can post pics for us to make sure you have the right ID on these guys?
A 10-gallon is too small for two, even cramped for a single, GTF. Then again, GTFs are not supposed to be 1 1/2" long... mine are all nearly twice that.
Animals should not be mixed, except maybe compatible animals by experienced owners in large (greenhouse-type, usually) enclosures. The animals you listed weren't compatible, they live in different areas and environment types, they are supposed to be different sizes, and fire-bellied toads are highly toxic.
If they survived this long, I'd be happy about it and get them all checked out by a vet to make sure that nothing is going on. However, now that you know better and can separate them you can be sure they'll live much longer and happier, not to mention healthier.
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Got hips like Cinderella / Must be having a good shame / Talking sweet about nothing / Cookie I think you're Tame 