Action Plans in Financial Services Cloud should support Task dependencies. In most real-world scenarios, a dependecy is required. As an example, take a New Client Onboarding workflow:
A task for submitting paperwork to the custodian should not be assigned until a task for collecting the signed paperwork from the customer has been completed.
While it is impressive that FSC Action Plans work very nicely with Account Teams and Business Hours, the dependency aspect is definitely a gap.
The Salesforce Labs Action Plans app does support dependencies: