No, not with your M-series device. On that device, a finite pulse train uses both counters -- one to generate the pulse, one that's used in the background to gate the other with the precise timing needed to control the # pulses.
One of the advances of the X-series MIO boards is that finite pulsetrains only use a single counter.
One sneaky trick I've suggested is to make a dummy finite AO task that simply generates 0 V, but export its sample clock out to a PFI pin to be used as your 2nd finite pulse train. (You could do the same kind of thing with an AI task if that's otherwise idle.)
Thank you very much for your answer. Kevin