It's really hard to get to a workable particle size distribution when starting with silt or clay, for sure. This is why "add sand to improve drainage" is often

It's really hard to get to a workable particle size distribution when starting with silt or clay, for sure. This is why "add sand to improve drainage" is often such terrible advice. People picture sandy soil that drains well, but by adding sand you're usually dragging the soil mix distribution towards the finer end and will make it worse.