We have Microsoft 365 Apps for enterprise (device) or Microsoft 365 Apps for Education (device), however, in order to assign these licenses you must be a Global Administrator.

Account with Service Administrator and Billing Administrator seem to be able to assign all other licenses.

We feel that the GA role needs to be RBACd down for the licenses to be assigned by service admins.

We know the GA role being required is documented here but there is no explanation for the reason such a high level role is required.
https://docs.microsoft.com/en-us/microsoft-365/commerce/licenses/manage-licenses-for-devices?view=o365-worldwide#assign-licenses-to-devices