With two transformers in series they both have the same current (by definition of a series circuit).
Two transformers in parallel will share the current based upon their output voltage difference (the two will never be exactly the same) and by the difference in their winding resistances. Unless you know both, you can not determine how the currents will be shared in parallel. (And, of course, the two transformers will need to be connected so their outputs are in phase, otherwise a very large short circuit current will flow).