I think your note on the compulsion to do EPIC story hits the nail on the head: less is sometimes more! Growing up reading Tolkien and other fantasists, I just had to go with an epic story, thinking maybe not the scope of The Silmarillion, but definitely the scope of the LotR. Ok, so first thing, I need a party with a wizard and a dwarf and two warriors, check... jk! I just wish I kept drawing short stories for a lot longer before taking on a major plot.
Challenges of writing and managing multiple subplots and characters aside, taking on short stories would have let me play more with different art styles. Trying something new for a couple of pages art-wise and then realizing it's not that great is fine for a short story, but jarring on the eyes within the same, much longer narrative. I started with a meticulous pen-and-ink work, only to realize it's way too time-consuming, then made a noticeable shift to more economical inking, and recently started adding a gray watercolor wash for midtones. Because it's a longer story, I had to try and make the art-style changes at strategic points in the narrative, and even that I find is still somewhat jarring.