Proxy models compatible with Games Workshop's Epic Armageddon to represent your Astra Militarum Imperial Guard infantry formations.
Epic Armageddon is out of print and the models can be hard to find. Use these to sub for your games.
UPDATE: 311009AUG17 After trying several times to print the original files I've followed another modeler's suggestion and increased X and Y dimensions of the figures by 20%, and Z by about 10% to preserve the proportions. Test print of a single figure was successful.
So I've seen this made a time or two and I've had a go at it myself. When I make designs for Shapeways I'm designing for an SLS process, and sometimes for SLA. PLA extrusion methods seem to be a little hit and miss at this scale.