Were S. Asian weapons designed to be used together?

[shayde78]

I was flipping through my old copy of Stone's 'Construction, Decoration, Use of Arms'', and noticed the image (#1) listed below of a katar with an additional blade at a right angle to the main blade. This made me think about the design of a bichwa I own, specifically the grip.
The Indians understood ergonomics, so the very flat grip has puzzled me. The hilt is clearly designed to fit the hand around the palm, rather than the fingers. This allows the fingers to be free to grasp something else. I have toyed with the idea that the feature may have allowed archers to draw their bow, but still keep a close-quarters weapon on hand (literally!). I have not been able to find any representations of such a use, though.
However, this image in Stone made me think about how well a katar and bichwa might pair. Below are images of what I have at my disposal to test the theory that these may work well together. Indeed, the two examples pictured pair together VERY well. The thin bar of the bichwa hilt fits flat and snug against the cross bars of the katar. Amazingly, my hand seems to fit much better on the otherwise cramped katar hilt because the bichwa grip serves as a spacer so the less meaty part of my fingers are actually gripping the hilt. Also, the guard of the bichwa provides nice additional protection for wielding the katar. Altogether, they make a very comfortable and probably effective weapons system.
I'd love to hear from others who have access to additional forms of these two types to see if they agree with this assessment. Apologies if this has been discussed already, but I was unable to find a similar thread.