I got this idea from the swappable head in the Clone Evolutions set, so good work Hasbro. Thanks!
The concept of this product would be just like that of the build your own lightsaber product, but it would be for 3.75" clone figures. These figures would have various pauldrons, straps, skirts, and heads that could be switched out to make unique clone troopers.
It would be nice if this set could include some of the helmet designs seen in the movies but not yet offered in figure form, though obviously a wider range of heads would increase manufacturing cost. However, if future single-carded clone figures were made compatible with the extra parts from this set, it will increase the life of the product. Also, future single-card clone troopers could even come with loose heads and accessories packed extra to build interest in this more expensive Build Your Own Clone Trooper set.
I suppose stickers could be included to customize legion colors. Though I am not keen on the durability of stickers, it seems like the only good option, and if we're customizing clones, you might as well go all the way.
Hasbro, if I may be egotistical enough to applaud my own idea, I predict the responses to this idea will speak for themselves.