Microsoft 365 licensing Help

You already got the answer but just to say you'd be giving up a lot of functionality by going down that route (Microsoft 365 Business). Depends though on which features you're intending to use or use already, Azure AD Premium, Azure Information Protection, Office 365 Message Encryption etc, as well as the Intune bits.

Looking at the costings would be interesting, though some of these combos might not make sense

Microsoft 365 Enterprise E3

Microsoft 365 Business with Azure AD Premium and Intune add-ons 

Microsoft 365 Business + EM3 E3

An interesting distinction according to that FAQ is to get the most from Microsoft 365 Business Windows 10 PCs need to be joined to Azure Active Directory. They can be connected to the on-prem AD but it's not recommended.