rentention policy

Hi,

I have a content type and have associated 2 workflows to it. I also have a rention policy applied to it to start workflow 1 on a specific metadata column and then workflow 2 on date column + 3 weeks. From what I understand is the retention policy timer job runs weekly on SharePoint online which basically means the dates I add cannot be used as they are reliant on where they occur in the timer job week routine. 

Any ideas on how I can improve this? I dont really want to have a workflow that is actiavted per documents as the library could contain 3000+ documents. 

Dhiran