[Waka]

Quote:

Originally Posted by Kiwami

I feel like an idiot for not noticing this sooner, but I realized why Sword & Gun Form are one set: The back part of the armor is identical on both. This means they only have to include one of these pieces instead of two.

There's probably one back piece, two different fronts (Sword & Gun), plus a faceplate, belt-piece and shin plates for both. So Rod & Axe Form is another set, simply because they also only need one back piece since it is identical on both forms as well.

This isn’t about which forms make sense to be sold together from a story or popularity-point of view, it’s to save costs on plastic and paint

Yep, that is exactly why. In the show, Den-o basically only has one armor that gets swapped from front to back, and/or opens up for different forms, just like his weapon. Only exceptions are his upgraded forms and wing form.