You know, some have criticized that the demi-human races in AoI can be paralleled to standard AD&D races. As I've said, I don't find that something criticizable. We're better off with a set of races that very generally follow the same set of niches as the ones gamers have been using for 40 years now; rather than presenting a bunch of races that are night-unplayable in their weirdness. The fact that the races that are in AoI were all chosen right from the Indian sources, and in versions that were true to these sources (or at least, to SOME of the interpretations of these sources), is the important part, and points to the ultimate commonalities in Indian and Western Mythological cultures.
And again, NONE of the races chosen in Arrows of Indra (save humans, of course) are a carbon-copy imitation of an equivalent D&D race. They all have significant individual aspects. Gandharva are perhaps the closest in aspect to a D&D race (elves), but I think even there, their strong religious element ("profoundly religious" not being something you typically associate with "elves") marks for an important difference.
Rakshasas are pretty much their own thing. You can maybe put them on the same spectrum of "type" as the Tiefling or Half-Orc, but they come up very different.
Vanara share a few traits in common with halflings, but again, they also have a bunch of qualities that make them stand out, starting with the fact that they're monkeys (and all that entails).
And now we come to Yakshas. Dwarves, right? I mean they're short, bearded, live on mountains, love gold, like to fight, right? Dwarves.
Well, not exactly. Yes, they are clearly a Dwarf-like race (which the Indians had as part of their mythology along with just about every other human culture...), and they like to fight. But let's note first that they live ON mountains, not "IN" mountains; that's something of a difference right there. Yaksha cities will be built on the surface, or within the very outer edge of a mountain, not somewhere deep below. They may be found deep below, however, because sometimes they're obliged to go down there to protect some treasure of Shiva's, but they don't really love being underground.
Ah yes, they're also religious, like the Gandharvas. Huge devotees, usually of Shiva but sometimes of Indra or other gods. Aside from being tasked with guarding the god's treasures, they are also entrusted to act as guards and guardians of sacred (Magical) places, places of divine power on the earth.
So let's start with that, then: the Yakshas are a race that exists, that was created by the gods, to act as guards for the gods' treasure. If you start with THAT as your defining element of culture, purpose and nature for the Yakshas as a racial type, you're going to end up with something rather different than Gimli, son of Gloin.
They live in the same places as Gandharvas, and the two races are best buddies. Not much like Elves and Dwarfs in most worlds, but it makes perfect sense if the former are the Gods' messengers and entertainers and the latter the gods' treasury-guards. And they're both ultra-religious.
Yakshas spend a great deal of time in lengthy and ornate religious rituals. They also love and deeply value learning of all kinds, and are considered deeply erudite. They'll often pause in the middle of things to give longwinded lectures meant to educate others, especially the lesser races (like humanity). Again, I don't typically think of Greyhawk Dwarfs as being extremely dedicated to learning or great lovers of philosophical discourse.
They are, at the same time, deeply emotional beings, who can be prone to bouts of passion, depression, and wrath. If the mythology is to be believed, they're prone to falling in love with any half-decent bit of leg they cross paths with, regardless of species. And when in love, they write poetry; and if that love is spurned, they either become whiny depressed emo-types or they go on blood-soaked rampages.
That doesn't sound much like any stereotypical dwarf-race I know of from D&D.
What it does sound like is a race that is approachable for gamers, particularly old-school gamers, who are used to playing dwarfs; but are in fact a completely new "take" on that niche than what you will find in a standard game. In other words, the best of both worlds.
Currently Smoking: Stanwell Deluxe + Image Latakia