Short answer is yes. Longer answer is what it is you are trying to accomplish. Perhaps if we look at the hierarchy of the issue types it would be helpful where:
Typically, an Initiative is considered to be more of a project level but usually is an initiative in a project (actual Jira project) with really big tasks as Epics under that, the break out of tasks to accomplish the Epic under those, and subtasks if needed to accomplish a given task.
All of that said, it comes back to how you want to organize your world. The 4 tiers are helpful. However, another element added in like Structure to further assist with organization and visualization.
Both the benefit and the curse of Jira is that it is what you make it. The upside is that, if you make a mistake and it's not working out, it's always fixable.