A bit of feedback about the picture composition.
The heroes being crowded around the stairs, with the rest of the scene empty actually makes the scene look rather deserted. It's an extension of the
Offscreen Inertia principle - if you scatter the heroes across the scene, it will convey the impression that there's a lot more of them. The reduced density might even work to reinforce that, as individual heroes, being much less obscured by each other, will be more easily identifiable.
For example, compare this still frame from the Unity Rally composite.
Because there are no visible "edges" to the crowd, the brain instinctively concludes that it must therefore extend indefinitely.
Similarly, I think that if you fill out the outside of the red line {so as not to obscure the Statesman Ghost and the city hall} with heroes, it might create a better "a mass of characters" impression.
That's my take on it, at least. Bear in mind, I'm not a graphics designer or artist, just a general sort of troubleshooter, so take my advice with a grain of salt.