Apparently we need to be able to recondition bowlers thinking, I don't think so. It is not that difficult to figure if a ball has the same name than it is part of an extension.
Element, Element Au79, Element Zr40 sounds like a line to me. It has been that way for the past 18 years that I have been designing balls. One would assume that the black hammer and the blue hammer and burgundy hammer were a line or the Zone, Danger Zone, Danger Zone Black Ice etc were a line, so why do the rules change today.
The Vendetta is a line, the Thing was a line (all 3 complimented each other), the Energy (same core 3 different covers was certainly a line) all 3 complimented each other. The Critical Mass (ha ha ) as you stated incorrectly, The Centrifugal Mass is the start of our Assymetrical line. By the way the Critical Mass was followed by the Code Red (another line). We probably do the best job at building arsenals and are on this site preaching less random purchases and more arsenal building than anyone else. Hope this clears it up.