Deciding which hero to level is an important and tough decision - as so many factors are involved: Your overall roster, synergy with other heroes, balancing heroes roles / colors … and more.
In the following exercise, I tried to create (based on public knowledge/guides/discussions), and the Hierarchy of heroes by roles.
E.g. Sabina is not a Great Hero commonly praised, but she (or melendor) have important roles as Debuffer. If you have 10 Ascended heroes without a buffer - you probably miss it (Seen players with very strong heroes but missing this role, hence having troubles in some fights)
Placing heroes in a hierarchy can never be accurate not have the same meaning to all players - but I still thought it worth the effort as a quick reference / rough guideline players can refer to.
Here it is:
Any feedback will be appreciated.
I do this much also to get feedback and hear more perspectives.