CRM - Workflow Rules to be applied and work across modules

CRM - Workflow Rules to be applied and work across modules

Hello, 
It seems that you can't use workflow rules in CRM to work across modules, is this correct? I need a customer account status to be changed IF there have been no new deals or new quotes in the last 6 months. I can't see this is possible? 
I can create a rule based on the quote module. I can create a rule based on the deal module. But I can't update or manage an account based on the activity in these 2 modules. 

Surely workflow rules should work across modules as many modules are linked to a single record?