I personally prefer the one with the line art since it has their faces and the gaps in the colors cant be seen, but I feel if you were to clean up the lineless version it would look great. You have a good sense of depth and have a consistent light source on all the subjects in this piece so that really helps elevate its quality. The lines are a bit messy, which is not by itself a bad thing. I follow an artist on twitter who does fantastic sketchy looking art, but I feel if that is the style you want to go for a brush with some texture would help. I'm going to take a guess and say this is the "Darker Pencil" tool in Clip Studio with the brush density turned down a bit. The issue is that you'll end up with unintentional dark spots where the lines overlap and its transparency on every other line would make the silhouette hard to distinguish IF you had a background. Overall, very cute, great lighting, recommend textured, darker lines.