Using a pair of 220v-110v transformers together
That won't hurt anything (until you put a load on there) but it also won't work so well. As you can see, the same current is going through both coils. The lower voltage on the primaries and secondaries means that the core is going to be less utilized, so they might be a bit more efficient, but basically you'll be stuck with roughly the same current rating and poorer regulation. 

If (and this is a huge if) both transformers were identical you might be able to parallel the two secondaries and primaries (taking great care as to phase, or you'll release the magic smoke). The slightest difference between the two transformers (even a slight one or two turn error in manufacturing the primary or secondary) and a lot of current could flow between the secondaries (resulting, potentially, in a lot of heating). 

It would be better if you could split up your load between the transformers, or just use a bigger transformer.