Our current structure is a compromising solution. I didn't want it to be like this. At first, I wanted the researches to be "linear", aka you HAVE to get 2-slot before 3-slot. But then there's a problem, we don't have an icon that indicates 2-slot weapon is a weapon AND a branch(contains 3-slot weapon). If I use branch icon, people might not think they would get something for researching that. If I use weapon icon, people might not notice 3-slot weapon at all (I think this is worse). So yeah I needed new icons, but for reasons I am not getting the icons, so I had to find other solutions. 1: Simply make it like vehicle MG, you get both 2-slot/3-slot with a single research. The problem is obvious, we would step into late game way too fast, like you can unlock 3-slot weapon literally at 10~15 minutes mark. 2: We simply put both 2-slot/3-slot weapons in the same branch. With our current "creative" names, it'd be pretty confusing as it's not all that easy to tell which weapon is 2-slot/3-slot. Putting the info in description is a pretty passive solution, it's like "oh hey we put it there, it's your fault for not reading it". 3: Of course, just ask programmers to add "prerequisite" research, aka set it so that you HAVE to get 2-slot before 3-slot, even if 3-slot is right there for you to click. Takes a lot of effort to code, of course. So yeah, I ended up with our current structure. It's like vehicle chassis if you take a look at it, you can rush heavy tank as you can rush 3-slot.
Absolutely agree - this will be much better when we can redo that UI so that you can always see researches leading to others, like in the Civ tech tree.