Hi Devuja,
As Stephani suggested, populate marketing email To field by assis-edit would be a useful way to send marketing email to not only contacts,
what's more, it could be possible to send marketing emails to related leads or accounts.(But contact is still based entity)
I just would like to add some supplement about the method:
By default, relationship Owing User(Contact) -> User might not be available in assist-edit,
we should enable the entity to appear in assist-edit by configuration: Advanced settings -> Marketing setting -> Marketing data configuration -> User(systemuser).

What's more, there are other two points that I would like to share:
1. Due to there is only one To field in marketing email entity, so we should create 2 same marketing emails to
let both contacts and owners of the contacts could receive emails.
2. Owner(user)'s interaction will be counted as contact's behavior.
For example, in a sent marketing email insights tab > Delivery > Sent emails, owner's primary email will be regarded as contact's email address,
This might causes confusing for us while we were viewing Insights data for a single contact record.
Regards,
Clofly