You could run an update rule through your form processing steps that would incrementally increase a numeric field and then base your lead scoring for form submissions based on that field. i.e. every time someone submits a form, run an update rule that says "if value of field = 1, then update field to 2, if value of field = 2, then update field to 3, etc." then allocate points in your lead scoring module based on the value of that field. Let me know if this makes sense.
-Jenny
