best practice for admin accounts in hybrid environment

HI
we have an on prem infrastructure alongside O365 in a hybrid
currently we have our IT staff using just 1 account which has elevated privileges
They use this for logging onto their own machines and for providing support to end users and maintaining servers.
this account is synced to Azure AD
In Azure AD they have service rights for the cloud apps
To leave this more secure im thinking of reducing these accounts to a standard account and creating a new high privilege account for local infrastructure and cloud infrastructure.
What is best practice?
Should i go with

1 local standard account synced to 365 using a license
1 local admin account
1 cloud admin account shouldn't need a license for administration

or

1 local standard account synced to 365
1 local admin account synced to 365 using a license