Form Flow: Avoiding Overwriting Certain Data if...

So we have a subset of folks for which it *may* be important, on occasion, to avoid overwriting certain associated data.

I now realize there are other ways around this, but for these cases, we created separated marketo first name, marketo last name fields.

My question: I’d like to run a smart campaign that copies the marketo first and last names in the already existing first name and last name fields, ie:

Change data value ‘marketo first name’ to {{lead.first name}}

Will that work? The other method would be to export all subs, manually copy the fn and ln fields in the marketo fn and ln fields, then reupload.

Thanks,

Dan