Yes.
Because of that, when using MAR, Multi-tasker then allows you to ignore the secondary target penalty when using MAR to split attacks.
"and choosing to hit the first target again if it doesn't go down. "
This isn't true though. You're supposed to declare the split on to targets before rolling any of the attacks rolls, not roll one or more at a time then decide. "Ain't nobody got time for that."
Ah, I think I misread, you meant Multi-Tasker does allow the same target. That is correct, Multi-tasker has that beneift and MAR splitting does not.