You're only looking at one side of the coin right now. I want to give you some more insight, I'm not saying it's just because of that, it's generally so that you can look at it more broadly.
The bottom line is that we have the necessary staff of people, our core artist is very skilled and can accomplish almost anything. BUT everyone has performance limits, she can only draw a certain amount of art per month. For our project to grow, we need to attract more and more new and talented artists, and as you may know finding people who can join the team is not so easy, especially for an 18+ project, it's my personal experience. I'm not even talking about making sure everything fits and stuff.
Next we take our setting, a huge abundance of artists draw mostly people. (Not talking about the current furry trend), generally speaking, this is again what I've experienced. So, basically a lot of people do not know how or have no experience drawing creatures, do not know what StarCraft is and stuff, and that's where we are saved by Stukov, why? Because this is the only male character that is a human (Terran), familiar to almost 90% of artists of all stripes.
Why am I saying this? Because really not everything is so rosy when it comes to finding artists for the project. I'm not talking about regular team members, you can see that many scenes are different from each other, have some changes in the style of artists and stuff, it's not our intention, it's all part of life. Someone comes to us, someone leaves, and this is the basis of 18+ game development, many people do not want to spend a lot of time on this, as such work can not even be put into their portfolio (I say if they are counting on a career in AAA projects).
Next point, is of course the desire to do the usual scenes with human on human content, human anatomy is beautiful, and there are a lot of great reference ideas that we want to implement, implement because someone asked for some pose, we were inspired by the idea, but with zerg or Abathur it would simply be impossible to implement, and that's where Stukov comes in.
This is just a small part of the iceberg I told you about, in fact, we can talk about it forever, and most importantly, do not think that we want to harm our project, and that we deliberately do what you do not like. You have to understand that no one will ever be able to please everyone.