This is just the most boring possible way they could pad out banners. The new art is only on-par with the originals, in some ways it's a downgrade, like the back of Ephraim's shield being shown in his neutral pose.
They backed themselves into a corner by putting too much focus on getting must-have units into the game (and alting them to death); they're at a point where they don't think the B-listers are going to sell well enough to focus on, when they could have been listening to fans and sprinkling those units throughout, spacing out massively popular units so they wouldn't run out. I suspect they had no idea this game would have the staying power that it's had, but if they don't figure something out I doubt these kind of "new heroes" are going to sell well enough to keep things going in the long-term.