Change required in Intercompany rules

Hello,

We have 3 entities 108, 113 and 122. we have a requirement that 108 should be able to do intercompany transactions with 113 and 122, but 113 & 122 should not be able to do intercompany transactions among themselves.

Current intercompany setups under primary ledger are:

Transaction Balancing segment = All Other

Trading Partner Legal Entity = All Other

Trading Partner Balancing Segment Value = All Other

These intercompany rules have disabled delete button.

Could anyone please tell me why the delete button is disabled? Can this be enabled to delete existing rules ?

If yes, What could be the impact of deleting the existing rules ?

Thanks,

Lakhvinder Singh