I've been giving this some thought since we last discussed it, Tom. I'm drifting away from this line of reasoning.
The category "dha" covers a broad range of weapons from an area large in both geography as well as culture. Uniting the weapons we think of as "dha" are elements lacking in the knives you refer to. They are, in my mind, too wide and lack the cylindrical handle common to dha.
Also, while I'm sure they make fine weapons (so do kitchen cleavers) I believe them to be tools first. Dha are usually weapons first, with the line blurring especially when one starts to consider the machete-like dhas of the kachin and "Montagnards".
What do you think. I've got a few of these (including a cool mak I got from you, thanks
) and they remind me of the old yard tools I've got from my grandfather in Pennsylvania.