Can my husband and I have the same email but different passwords for 2 separate iCloud accounts?

Even you try to create two separate icloud accounts with same mail address and different password it can't be created because the credentials for each account like three answers for security questions , date of birth , rescue mail address and its password , credit card details will always be different , you can't copy the same credentials and create the account for second time on different device the server won't accept it .

The credentials , apple id , password are interconnected and confined to an individual account see the article Security and your Apple ID - Apple Support

Apple requires an unique email address for each account created.

Depending upon the email service you use, you may be able to set up mail forwarding with that service to multiple addresses.