I'm seeing Marvelous Designer used more and more for character clothing designs. You can attach some fabric elements (jackets, padding, straps, etc) onto the hard surface elements and answer the question how it would actually be worn in reality. You can also stretch some fabric elements over the character's body and then export them as a new mesh to be combined into your final armor model.
Just had to pop in and say thanks for mentioning this. Never heard of this product and it looks like a great tool.