While I concede that LWX can be a little trigger-happy on the warnings, you seem to be asking for a level of precision that simply is not available given the current state of the science. Thunderstorms are inherently unpredictable--in where and when they form, how strong they become, and when they decay. The best meteorologists can do is issue warnings for an area that appears to be at risk for severe weather. Occasionally that risk will manifest; most times it won't. The alternative is to only warn storms they are certain will be severe, which will mean that the vast majority of storms that produce severe weather will go unwarned.