Having visited some factories and spoken witha lot of cigar makers on this topic, I can definately shed some light here. A lot of the cigars out there that are labeled as seconds are not really seconds. They are actually cigars made as themselves (firsts) and are not throw outs, they are their own unique blend. Most makers do this becuase they dont want to canabolize their own cigars with lower priced lower margin items. However, they do usually use left over or lower grade tobacco from their existing lines but just reblend it. It is mainly the retailers who brand the cigars as seconds at that time. For example, Private Stock is really its own brand but it does use some scrap tobacco from Tabadom, but so does the M1 by Cusano. In this regaurd the M1 by Cusano is ijust as much a davidoff second as is the private stock. But really I dont think you can consider either cigar a second.
The only cigar maker I have come accross that truly sell seconds of a premium line is Rocky Patel and perdomo on occassion. If any other cigar makers makes a bad cigar that is not deemed a first they either 1. throw it away, or 2. take it a part and use the tobacco as a mixed filler in a less expensive cigar.