Interesting, who published the Journal of genetics?
All the references to showring standards I've seen was always only a description, I can't remember ever seeing the diagrams. All of them say ideally the white crest shouldn't go back further than the withers on the back, there must be a break between the white head and the white crest. White shouldn't be above the knee or hocks on the legs, excessive white on the flanks is undesired. The entire head must be white without red spots, the horns without pigment, no spots on muzzle etc. It also states that less white is equally undesirable and that red legs, red necks and linebacks should be discriminated against.
According to your diagrams my two bulls is probably closer to a 0 and -1. In the traditional hereford genepool in the UK, which is without a doubt the most pure hereford genepool in the world, -3 and -4 is the norm rather than the exception.
In the UK and in the 3rd world petty things such as a touch too much white or too little white don't affect sale price and will only come into play in the showring if two animals are absolutely equal otherwise.