Speculation. Every 3-4 end in history has suffered a drop in statistics, and check it, an end operating in the 3-4 has never led the league in sacks. Domination in the 3-4 looks much, much different than domination in the 4-3. Would he? Probably. But we don't know.
I find it hard to argue with the fact that Spears doesn't have the physical tools White did. Reggie White is arguably the greatest D-lineman in history. However, I found it curious that you picked him to compare to a rookie who played in a different set, which makes a monumental difference. Kind of skews your argument.