Before going into that, why have you kept the same EG and ESG for all the countries?
Is the meaning of a particular EG same across all countries? If yes, you can keep it.
Your holiday calendars and leaves are defined at personnel subarea grouping level and not ESG grouping level. PSG grouping represents your location.
All your quotas will be a combination of ESG grouping and PSG grouping - employee specific characteristics and location specific characteristics.
You can use the same EG and ESG if the meaning of the EG and ESG is same across all countries.
If they are different, then go with different EG and ESG.
Thanks and regards,
Vivek Barnwal