I think he wants to parallel the transformers output to the track for an amp increase.
I wouldn't bother with that as both throttles would need to move to lower speed...i.e. delayed slowing.
Doing it in series would double volts.
Dc doesn't have to be phased to the AC .
Dc can be paralled for capacity (+to+) or stacked in series like flashlight batteries (+to-) to add votages. Some new age power supplies with fancy regulation might not like any of this.
You could divide the track into blocks by loop or sections, and use both throttles separately, one on each block. This can be useful for speed control in some spots or if you have two loops and running two trains on them(connected or not). (this is where two handles on one transformer shines toio ... or at least screwing your small ones down so they can't squirm away with no second hand ro steady things....the blocks are nice for running lots of powered cars (with lights, etc) Old bulb amp usage adds up fast, blocks can help split the load for a spell.
You also might want to save it for powering turnouts or accessories so they don't effect the train and train doesn't effect them (pulses, dimming, etc)
