This is an absolutely 'textbook' thread!!! and Brian, thank you for posting this very scary looking mace which has brought the term 'discussion' back into the mainstream here.
I must say that my initial reaction to this profusely spiked sphere mace was as with others, not necessarily a combat weapon but more parade or ceremonial. In searching online, I found the khanda hilt form of one of these on the Oriental Arms site (the one with blue background in the photos). In this it is described as Rajasthan, 18th c., and in many years of experience with Artzi, his descriptions are typically pretty reliable,so that seemed a good benchmark.
Estcrh showed a perfectly supported rebuttal to indicate that these were indeed probably quite combat useful, and the suggestion of the spikes preventing deflection off armour seemed reasonably plausible. I think Emanuel added a most valid view concerning the dissipation of penetrating force with more spikes, which are dynamics often not considered in looking at many weapon forms.
At this point, I am inclined to reconsider this may well be a combat form of mace, however, the rather open means of holding this with simple bulbs on the haft rather than the more substantial sword hilt or more pronounced hand stops remains suggestive of a more votive piece.
Many weapon forms were somewhat vestigially produced for use in temple ceremonies and processional instances.
The main purpose of the mace as I understand it is to crush and compromise armour, either to render the wearer immobile or unable to defend himself, and often to break or open the armour to gain an opening for stabbing. Clearly this would apply to plate type armour, but in India, oftenwe would be looking at mail or heavily padded cloth protection. With mail there would be a distinct threat of this becoming lodged, as well as with cloth. This returns to the case of losing the use of the mace by its being lodged in the victim, but does not preclude the concept of its use in combat. In the case of most of these warriors, they were of course armed with numerous weapons, and arms are often 'staged' in battle situations .
In many cases 'shock' action initiated attack, and often the weapons used in this opening action were often discarded as combatants moved to their secondary weapons. I would think that a line of infantry warriors charging forward with these horrifying spheres would create a most disheartening effect on their opponents.
Fascinating piece Brian!