No. you do not need a cutter - if - you don't mind mixing room temperature lard and flour with your hands; I've done it both ways. I prefer hands, but not everyone likes the feel of sticky, greasy dough oozing through their fingers. Cook it on a hot cast iron skillet or griddle. .
IF you work the cutter long enough the ingredients will be properly blended and you will have a good, but as fine "meal" to work with that you would achieve by pulsing it in a food processor. .
Murphy's Law: Shortly after you begin mixing dough with your hands the phone will ring. Then the doorbell will ring because you did not answer the phone.
I don't agree that spending $300 for food processor, french rolling pin, off-set spatula, exotic flours and oils will make any better tortilla than a Mexican grandmother, afterall, the tortilla has been made the same way for 100 years.
Lighter weight versions of professional tools can be puchased at most better quality retail stores and cooking boutiques. I buy professional quality tools at my local restaurant supplier because they are heavier, better constructed, and last longer. Tools are only as good as the care they receive, anyway.