Absolutely Ibrahiim!!
As you well note earlier, the cross as a symbol or device, like many others, is often convergently known in many cultural spheres with equally diverse interpretations. Textiles and materials typically carrying extensive motif often incorporate these various symbols and devices profusely, and offer us many opportunities to compare to such detail on weapons as noted here.

Good work on the astronomy as well, and while I know the Southern Cross term is I think of course key to our friends 'down under' in Australia and New Zealand, the constellation is of course also well known far to the north.
As in many, perhaps most, ethnographic societies it seems cosmological themes are well observed in lore, tradition and folk religion.

As you point out, the character of these devices on the terrs seems to reflect Ethiopian influence. Perhaps these Agadez crosses, or even the ancient Egyptian ankh, may have filtered into the crafts of artisans there?
The diffusion of these kinds of nuances through centuries of trade of course has no bounds.

HERE ARE SOME PICTURES OF A SHIELD THAT SOLD RECENTLY TO ADD TO THE REFERENCE.

Salaams Vandoo ...Excellent support and backup pictures thanks...
Regards,
Ibrahiim al Balooshi.

Here is another Ters where a lathe has been used to shape the outer surface.