Need advice on the artbook.

 I'm asking here because of dilemma I'm having with my Doujin group..kinda we don't share the same opinion or suggestion because the artbook didn't sell very well during the event. WE've done two artbook..and that is Vocaloid. I'm not saying its bad but.....it just didn't sell very well unlike the other artists booth.

My suggestion is to have freedom on the theme of the artbook is freedom. Random characters or ocs, but follow the theme provided like fantasy theme , dessert theme,  food theme or etc..pftttt

While the leader of the group suggested to do fanarts...Vocaloid again..with a bit of crossover. I'm kinda like...can we take a break from fanarts for the artbook and do others instead? idk.
She instead to pressed on the fanarts because she already told us OCS didn't sell well unlike fanarts though its only badges not artbook. but oh well....I'm so tired to argue with anyone due to my brain didn't work pretty well these past few days thanks to the sudden changes of my schedule.

So yeah...I need you guys advice, whichever is better......gg.