Hello & Welcome:
It depends on the design of the inverters in question.
Some types can be run in parallel, but they will need to be synchronized so that the AC sinewaves are in phase. This generally involves one inverter being "slaved" to the other, so that the outputs are locked together.
The inverters also need to be of a type which will not have their voltage regulation upset by being paralleled in this way.
By the way, trying to tie different branches from different houses together is not a good idea. One problem is that houses on different transformers may well take their high-voltage feed from different phases, so the "hot" lines will be out of phase. There are many other safety concerns as well, so I wouldn't advise anyone to try it.
