Ninjas – even though they are professionals, they are still ruthless thugs who lack honor. So, they don't fit into the overall samurai concept of the race. I'm surprised that there aren't geisha healers, and instead, there's a spirit. And women should be mages; female warriors in chainmail bikinis are already getting old. Besides, all three fit into the Japanese concept of the race. In this regard, the shark guardian is the most out of place. And the women look a bit alike, but let them look alike. They differ significantly in details, but in Heroes, you need to be able to distinguish the "top-tier" units at a glance, so there might be some confusion, but we'll get used to it.