"unfamiliar with any sort of advanced structures like temples or fortresses as we can subtract from the earliest Sanskrit and Avestan texts and etymologies."
This can be disproved with a quick ctrl+f.RV Book 10.107.10 :"This dwelling of the benefactor is like a lotus-pond, adorned and shimmering like the palaces of the gods"
RV Book 7. 88.5: "O Varuṇa of independent will, I went into your lofty mansion, your house with its thousand doors."
The same palace in the Avesta, Yasht 5. 101: "In each channel there stands a palace, well-founded, shining with a hundred windows, with a thousand columns, well-built, with ten thousand balconies, and mighty."
^ Doesn't sound like a Sintashta hut.
Many of these supposed BMAC loanwords have proposed IE etymologies such Indra and ustra. Assuming there is a substrate can we for sure say it's from BMAC? What if BMAC was Indo-Iranian and this substrate comes from Vakhsh culture, SiS, Mundigak..etc? After all, much of the "high culture" elements of BMAC have their roots in Mundigak.
Also, there isn't a consensus on the Aryan words in Uralic. Depending on the linguist they range from Proto-I-I to middle Iranian.
"Most likely early Indo-Aryan-speaking steppe nomads have arrived in the BMAC region around 2000 BCE, not necessarily as rulers, but at least as troops of elite warriors with their effective war machines and social structures."
1. There is no proof that the Sintashta chariot was a "war machine'. In fact, it is vastly different from the Mitanni chariot. According to Anthony they were used by javelin throwers: "Second, steppe chariots were not necessarily used as platforms for archers. The preferred weapon in the steppes might have been the javelin...When horse-drawn chariots appeared in the Near East they quickly came to dominate inter-urban battles as swift platforms for archers, perhaps a Near Eastern innovation". So Vedic chariots were a Near Eastern innovation? And what were these effective social structures?
2. Based on all the recent chronologies (Dubova 2020 and Gursan-Salzman) Hissar IIIB(2500-2200BCE) predates Sintashta by centuries.
"Due to the mass adoption of nomadic pastoralism and effective warrior societies"
Where? Yaz I and Late Grey Ware are pretty much continuations of older traditions. BMAC has been a warrior society since its conception from axes to depictions of defeated Jiroft enemies and Hissar even longer.
"With the desiccation that began around 1800 BCE, BMAC sites gradually became less and less populated, with its population likely joining the surrounding Indo-Aryan tribes to migrate with them"
There is no problem with your models. However, there are also models for Hasanlu and Alalakh that do not require steppe_mlba and use Yamnaya and Armenian sources instead. Which is more likely? Well, check out the following post 1500BCE samples from Turan:UZB_Bustan_BA:I11026
UZB_Bustan_BA:I4157
UZB_Bustan_BA:I4159
UZB_Bustan_BA:I5604
UZB_Bustan_BA:I5605
UZB_Bustan_BA_o1:I11521
TKM_Parkhai_LBA:I6668
TKM_Sumbar_LBA:I6675
Barely any steppe DNA makes it more likely that the steppe source of these west Asian groups is Yamnaya related.
The more likely scenario is when Late BMAC was collapsing there was perhaps a small movement from south to the steppes that brought I-I languages. "In the 2nd millennium BC settlement of Shagalaly II, between Kokshetau and Zerinda, in the Akmola region of northern Kazakhstan, T.S. Maljutina brought to light imported pottery of Oxus origin, or imitation, in stratigraphic association with Fedorovo and Alekseevka pottery" (Bonora 2020). See also, Taldysay and Kyzlbulak.
"unfamiliar with any sort of advanced structures like temples or fortresses as we can subtract from the earliest Sanskrit and Avestan texts and etymologies."
This can be disproved with a quick ctrl+f.RV Book 10.107.10 :"This dwelling of the benefactor is like a lotus-pond, adorned and shimmering like the palaces of the gods"
RV Book 7. 88.5: "O Varuṇa of independent will, I went into your lofty mansion, your house with its thousand doors."
The same palace in the Avesta, Yasht 5. 101: "In each channel there stands a palace, well-founded, shining with a hundred windows, with a thousand columns, well-built, with ten thousand balconies, and mighty."
^ Doesn't sound like a Sintashta hut.
Many of these supposed BMAC loanwords have proposed IE etymologies such Indra and ustra. Assuming there is a substrate can we for sure say it's from BMAC? What if BMAC was Indo-Iranian and this substrate comes from Vakhsh culture, SiS, Mundigak..etc? After all, much of the "high culture" elements of BMAC have their roots in Mundigak.
Also, there isn't a consensus on the Aryan words in Uralic. Depending on the linguist they range from Proto-I-I to middle Iranian.
"Most likely early Indo-Aryan-speaking steppe nomads have arrived in the BMAC region around 2000 BCE, not necessarily as rulers, but at least as troops of elite warriors with their effective war machines and social structures."
1. There is no proof that the Sintashta chariot was a "war machine'. In fact, it is vastly different from the Mitanni chariot. According to Anthony they were used by javelin throwers: "Second, steppe chariots were not necessarily used as platforms for archers. The preferred weapon in the steppes might have been the javelin...When horse-drawn chariots appeared in the Near East they quickly came to dominate inter-urban battles as swift platforms for archers, perhaps a Near Eastern innovation". So Vedic chariots were a Near Eastern innovation? And what were these effective social structures?
This also might be of interest. https://www.academia.edu/43434670/The_Introduction_of_the_Horse_Drawn_Light_Chariot_Divergent_Responses_to_a_Technological_Innovation_in_Societies_between_the_Carpathian_Basin_and_the_East_Mediterranean
2. Based on all the recent chronologies (Dubova 2020 and Gursan-Salzman) Hissar IIIB(2500-2200BCE) predates Sintashta by centuries.
"Due to the mass adoption of nomadic pastoralism and effective warrior societies"
Where? Yaz I and Late Grey Ware are pretty much continuations of older traditions. BMAC has been a warrior society since its conception from axes to depictions of defeated Jiroft enemies and Hissar even longer.
"With the desiccation that began around 1800 BCE, BMAC sites gradually became less and less populated, with its population likely joining the surrounding Indo-Aryan tribes to migrate with them"
There is no problem with your models. However, there are also models for Hasanlu and Alalakh that do not require steppe_mlba and use Yamnaya and Armenian sources instead. Which is more likely? Well, check out the following post 1500BCE samples from Turan:UZB_Bustan_BA:I11026
UZB_Bustan_BA:I4157
UZB_Bustan_BA:I4159
UZB_Bustan_BA:I5604
UZB_Bustan_BA:I5605
UZB_Bustan_BA_o1:I11521
TKM_Parkhai_LBA:I6668
TKM_Sumbar_LBA:I6675
Barely any steppe DNA makes it more likely that the steppe source of these west Asian groups is Yamnaya related.
The more likely scenario is when Late BMAC was collapsing there was perhaps a small movement from south to the steppes that brought I-I languages. "In the 2nd millennium BC settlement of Shagalaly II, between Kokshetau and Zerinda, in the Akmola region of northern Kazakhstan, T.S. Maljutina brought to light imported pottery of Oxus origin, or imitation, in stratigraphic association with Fedorovo and Alekseevka pottery" (Bonora 2020). See also, Taldysay and Kyzlbulak.