Bob Lum's tanto grind with the hamaguri appleseed tip is not really comparable to the Coldsteel tantos. CS basically popularized the American tanto, sometimes called the Westernized tanto, which has two separate ground edges and a tip that comes up at an angle. They're hollow ground with a saber grind on the tip as far as I know. The tip would only be stronger because it's saber ground instead of hollow ground like the main cutting edge.
On the other hand, Lum's tanto design does have a stronger tip because it's a dulled convex grind. It's meant for piercing just like "real" Japanese tantos were meant for. Lum's tip is what is called a hamaguri if I'm not mistaken.
Lum is credited with bringing the Japanese style of tanto to the states. If CS did steal the design, they made a poor copy of it.
EDIT: I know Lum made his first knife in '76 in his apartment using a home made grinder. What type of blade that was I'm not sure.