probably because the artwork is just the individual characters spliced together.
You've made a considerable advancement on the given source material.

That said, the picture suggests they all gathered to show their war face for a group photo, but we all know that is not the case.
I wonder if you would consider removing the characters you don't have a full a view of their faces. Also, consider removing the Marvel Comics M, the "fine print" and the Capcom logo. They look out of place and are for marketing and licensing. I know that in particular is more detailed, but I think it would look better.
Please note:
None of this is a criticism on you. You've done fine work. In general though, there are problems with this clip art style. A search will yield past discussions. More than likely this is why there wasn't more participation.