Negative Time Mgmt implementation

Dear Friends,

We are going to implement Negative time mgmt. for 40 locations(20000+ employees) each having different leave policy in terms of leave cycle, leave types, Leave quota, different accrual policy, and so on.

With same name say Privilege leave under IT2006 as subtype, can we handle all leave rules for 40 locations ?

I think with help of ESG/PSG grouping we can handle that. Can any one suggest the SAP Best practice in this scenario ?

Regards ,

Niladri