The new one is thinner than the old ??? The newy is spec'd at 9mm, so if the old one is thicker than that, it must be more like a little axe than a Khukri.

The new one also appears to have a longer handle - are they both from the same maker ?
FWIW, I think that the shape of the new blade would be more versatile than the shpe of the old. Enough of a curve/hook to be usefull without making it into a heavy weight sickle.
I'm aware of the hyped up military past, typified by stories told to me by my father post WW2, but these things are primarily an agricultural tool, so versatility and manageable weight and length would be more important than felling unrealistically large trees and the potential for killing people (usually

).