Opportunity and Accounts and Revenue Split

Here's my requirement
Account: Sales Office A has accounts

1) Account 1 with parent account of Sales Office A
2) Account 2 with parent account of Sales Office A
3) Account 3 with parent account of Sales Office A

I want to enable the Opportunity revenue split feature so for an Opportunity O, its Opportunity Team will have the below participants in it

Account 1 (let's say the split is 30%)
Account 2 (let's say the split is 20%)
Account 3 (let's say the split is 50%)

In other words, the above three accounts work on this Opportunity O so they split revenue.

But when you add someone into the Opportunity team related info, it looks for Users and not Accounts.