Using signup or closed group automation for a list synced with Zoho CRM? Will Campaigns treat new entries as new subscribers?

Using signup or closed group automation for a list synced with Zoho CRM? Will Campaigns treat new entries as new subscribers?

I am trying to create an automated email drip campaign for new leads inputted into Zoho CRM. So the flow is as follows:
  1. Sales person adds lead to Zoho CRM
  2. Zoho CRM and Campaigns sync leads to the mailing list
  3. Each NEW lead that is added in the sync should get the first email in the drip campaign and each subsequent email thereafter
Will each new person that is synced to the campaign list be interpreted by Campaigns as a new subscriber? And will they then START the email drip process?

Also - Should I be using signup automation or closed group automation? The list WILL be a fixed list however it will be changing on a daily basis as new leads are inputted into Zoho CRM. 

Thank you