A clash between Minamoto and Noritsune would be nice to see.
Regarding the gender of Antoku I guess the author can choose it or change it given it's fiction. It'd be very surprising if it's a boy. At least I like a female spoiled girl as rival of a genki Chiyo.
–- Update From New Post Merge ---
With that out of the way, about this manga. This manga is pretty nice. I have followed Nakayama ever since he has done Traumeister, so picking up Uratarou wasn't a question. His art has always been unique, and a fantasy setting gives him a great opportunity to outdo himself once again. It also explains why he was looking for assisstants earlier this year - this background game is insane and fits his artstyle like a straitjacket. Speaking of background, fantasy Genpei is rare compared to fantasy Sengoku Jidai, so that is a welcome change. If this this our Yoshitsune, I can't wait to see Benkei. Chiyo herself is a bundle of joy turned to the max. Uratarou needs some more work in depth department, but action wise he is outstanding. It is tough to get more metal after pounding your enemies with your torn off head, so this is a welcome challenge.
The art in Uratarou made me read some other titles of Nakayama. Depth plot is an issue in most of his series. Nejimaki's didn't grow on me since the motivation of the MC, a female student, is simply to marrie his teacher. The Zombie Maria is cute but, again, is lacking in depth; even so the dark zombie topic is a chance for Nakayama's gorgeous art. That can also aply to Love Suicide which is a funny comedy about a freak owner of a coffee; a good joke. So far I saw good art for dark topics and light-weak plots. That makes me think choosing Genpei War as inspiration for a historical manga can improve the depth of the story. It clearly helps the worldbuilding and itcan improve the depth of the plot. Also it really fits his great art since he can draw magical creatures and beings of the outerlife, which seems to help the inspiration of his pencils. I'm really licking this series.