Is it possible to have/connect 3 workspaces with one Salesforce,
I think that we can came up with a backed campaign that updates a value = name of the workspace and them on SF be able to see it (by governance) would it work? or do you have a better idea on how to do it?
Thanks in advance
Keeping in mind that you can only sync (1) CRM instance with (1) Marketo instance, the short answer is that yes this is possible.
You'll just want to be sure that the smart campaigns that push the leads to Salesforce are located in a workspace that can access the leads.
Here's a few discussion threads that relate:
Person Partitions & Salesforce Sync
Salesforce Sync with Lead Partitions Best Practices