Salesforce Sync Options
We are wanting to sync our leads from Marketo to Salesforce. Salesforce requires certain fields to be filled out in order to complete the sync, such as Last Name and Company Name. Since Marketo doesn't require these fields for every lead, it creates a sync problem.
In the admin section of Marketo, under the Salesforce tab, I see the following Sync Options dialog box. I'm wondering if the two boxes under Lead Information is where I could assign a default name to be automatically zapped into the lead record (if it's empty) so that it can successfully be synced with Salesforce. Am I assuming that correctly? Does it only change these fields if they are totally empty? Does it only change these fields when it is attempting to sync with Salesforce?

Thanks so much for any help.