I think you should go more for the Hindu / Indian style with Asoka. This is bearing in mind:
a) many of the other leaders on your list will be in Buddhist, Daoist garb which will look quite 'samey'
b) Many of them will thus be quite oriental / east asian in nature, whereas Asoka gives you an obvious opportunity at a South Asian / Indian style of dress - which is flamboyant at worst.
c) You can indulge in a some lavish jewellery, make up, crown as shown etc, which a more Buddhist leaning / dressing leader wouldn't have gone for. He did hit quite an ascetic streak in his later life. So going for the Buddhist option would be turning down that colourfulness.
d) The peaceful Buddhist presentation would also oblige you to not include the imaginative arms he could be adorned with.
I would refer you to that crown and those later paintings in my previous post for his ancient look, for all the reasons just given.
Now also the Industrial Age look. I think this is quite wrong. I guess with the suit and tie you are depicting the British Raj. Well after consideration I think this passage of Indian history is in gaming terms effectively one civ taking over another. So your thinking on this might as well lead to replacing the leaderhead with whatever conquering civ. But you still have some very Indian looking options during the British Raj period because the local leaders didn't adopt western dress. Major regions and groups from this period which you can draw on are:
This is slightly before Industrial age but they wore similar dress.
The Marathas (Shivaji - pre/early industrial. Note the eye shadow and lip rouge. British rulers and military types often commented on how camp Indian nobility was in its dress and mannerisms)
Don't let the swords in this pic mislead you about the time.
Nice Maratha style turban here.
Ranjit Singh (representing Sihk influence after the decline of the Mughals, early British days)
Bajirao
Tipu Sultan
Comparing with British Raj Solider
You've also got the later industrial age with Nehru and Gandhi
This was of course the birth of modern Indian nationalism, the Muslim / Benagli influence shown by Nehru's hat and jacket is a very good synthesis of the politics of the time.
