The verdict
For a small B2B team, I'd pick ActiveCampaign. You can start without a sales process, the CRM is included,.
I'd pick Marketo Engage when marketing operations is a role, you run Salesforce or Dynamics, and you need attribution that sales trusts. It is built for that setup.
The risk with Marketo for a small team is cost and ownership. Adobe sells four packages and shows no prices without a sales conversation, and programmes, tokens, smart campaigns and scoring models take time to set up well. Without an owner it becomes an expensive email tool. If your CRM is not Salesforce, Dynamics or Veeva, you rely on the API or a connector.