Marketo implementation on different country domains

Our company has portals in a few markets, each of them is on a separate domain:
company.com.es
company.com.tr
company.com.my ...

My key concern is data pollution: E.g. in Spain report I need to see the number of conversions for this country only

Please advise on the following:
- Munchkin implementation - is it ok to put the same code across all domains? Will the data still be tracked separately? 
- Tracking links - should I cretae a CNAME for each of the domains (e.g. go.company.com.es, go.company.com.tr ...)