I was just trying to see how they would look together once I get some nice building I will put them in a Bastogne dio.by the way is milliput clay? I have no idea what it is.

No - it is more of a two-part putty. It is a resin-based chemical substance that "works" like clay when being mixed, and then can be molded into almost any basic shape desired. It dries hard as a rock. It can then be filed, sanded, or painted just like plastic or plaster. The Options for making sandbags being discussed here would likely be made of either Milliput or a product called "Sculpey " - a special kind of clay that can also be molded, but then must be baked to achieve the desired hardness.