As a general rule, an intermediate block is rarely more difficult to make -- it just contains more pieces and therefore more seams. This is the reason that it is important that you can sew an accurate quarter inch seam allowance. Once you have mastered a precise seam allowance, you will have no difficulty in sewing the majority of quilt blocks.
Free Quilt Block Pattern
My only guess as to why this quilt block is named Cowboys is because of the movement implied. I can visualize a cowboy riding along, with his lasso winding around his head, prior to letting go to grab his quarry. Perhaps that is the job of the pinwheel shapes in the block. Again, this is only my interpretation.
This four patch block will require a little more precision than some other, more forgiving blocks, as it is constructed entirely of triangles. However, nothing is difficult to construct, so you should have great fun sewing this block.
The block is quite pretty in itself and makes a lovely quilt design as illustrated in the two sample quilts shown.