I have used that same test for windproofing for years, I call it the Huff Test. Hold the material to your mouth and give a huff. If your breath goes through with no resistance, so will a cold wind so it is a summer windproof at best. If you cant huff any breath through it will get too clammy. Ideally your breath will force through the material at higher pressure taking a couple of seconds to exhale.
If the material is suitable I look to the design. Is there good sealing around the openings or can I make it so (with a neck buff)
My first priority is a windproof outer, then a wicking inner, then midlayer materials. Ive ridden comfortably in cotton T shirts so i dont get too religious about it but by choice I use merino wool or synthetics.