The best use of the Rockwell hardness scale is for the heat treater to keep track of getting a known steel to a particular point of hardness while keeping very careful watch over the time and tempuratures used to heat treat. The goal being that fine line of both edge holding and toughness for a given job. Their are many wrong ways to get the right Rockwell hardness no. during heat treat. Rockwell hardness readings, which are very well explained in a previous post here, do not tell us the wear resistance or toughness of a steel in comparison to others. You could have two different steels with exactly the same Rockwell hardness no. that have very different qualities of edge holding and toughness. The metallurgy books define steel in it's simplest form as being made of Iron and carbon. Enough carbon in the steel makes it hardenable by heating and cooling. The difference between tool steels comes from the alloys (and percentage of same) used in the initial melt, some form carbides, some go to the matrix that hold the carbides, others work to improve grain structure and make the steel respond better to heat treat.. Their is nothing wrong with the knife you describe, lamination is a great way to make a strong knife that holds an edge very well.