I dont Know <-- gotta say that first.
these current control devices use a sence resister to detect the current flowing through them, when you tie them together the sence resister gets tied at one end, then through the curcuits things get tied back to the battery when parelleled.
the results are then unpredictable, it sort of works, then you can notice things going badly on the driver itself. and there can still be fluxuations that already do exist being compounded.
properly mashed together it will work fine. meaning you could probably tie them and adjust a few things electrically to make it work right, or filter the cross stuff, without taking all the throbbing and sencing and different currents out of the devices that will try and do eachothers work, and "flyback" to the other one.
With 2 completly different drivers and probably 2 different sensings of the current , 2 different inductors, chances are good it would be a worse matchup than anything, things would act up pretty fast.
beings there are 1amp drivers now , , , well.