Restricting SFDC visibility rules for lead partitions

Hi Marketo Community! Just some background info: there are two different companies sharing one Marketo instance (separated by workspace and lead partitions) and one SFDC instance (we identify each companies using two different record types).

We are having issues sending the correct Lead/Contact/Account Owner using tokens for Nurture Emails to Customers because the SFDC field mapping is either not synced to the correct or wrong Marketo Field. Is there a way to restrict SFDC visibility rules for specific fields from specific lead partitions? For example, if we have a unique Account Owner field that we don't want the other partitions to see, can we hide that from being seen?