I cannot see how a blade ground 40 degrees on one side would have any advantage in strength over one that has been ground at 20 degrees per side. As always i could be wrong, so by all means don't take this as gospel. I just don't believe there are many advantages of chisel grinds and tanto tips on a knife designed to be used for most tasks you would use a knife for.
+1
I think the stronger tip would have more to do with how thick the blade is than the type of grind. For certain tasks chisel grind might be better but for general EDC I would think V grind or convex would be better and just as strong.