Rules for Managing Child Accounts Across Sales Teams

Hello all, in cases where you have a parent account with multiple child/subsidiary accounts, what are your rules of engagement around letting the child accounts managed by different sales team segments? For example, if your Enterprise sales team services the parent account, do you allow your mid-market / SMB sales teams work on child/subsidiary accounts which have much smaller annual revenue? Would love to hear best practices around whether I should allow sales team covering different segments work on a parent account and its child accounts. Thanks!