that is the idea of stealth in general yes. because "reduce the range of a radar can pick it up" is "making it harder to see" and the goal of stealth. extreme stealth like the F-117 just reduces the range it can be picked up to such short ranges it can overfly radar nearly at will without being noticed.
but in this case you are talking it being a huge return no matter what. it just isn't shaped right to be stealthy. it is always going to be blindingly obvious on a radar screen, no matter how much radar absorbing paint you layer on it.
but Flight of the Old Dog came out in 1987, and obviously was written a bit earlier. the F-117 and its insights into how stealth worked wouldn't be declassified until 1988 and the actual revelations wouldn't percolate into the public mind regarding stealth and shapes wouldn't really come until 1991 and the Gulf War, where its use was widely publicized.
so the author wouldn't have known. and the previous decades of stealth focus was on radar absorbing paints (used extensively on things like the U-2 for example, bring its signature down from "freight train" down to "doubledecker bus") or experimentation with radar transparent materials like certain woods and plastics, to reduce the amount of stuff reflecting the radar back (turns out engines are huge reflectors of radar, and easily show up bigger on radar than airplanes themselves if they aren't buried inside the body of the plane.)
