By the 1600 BCE,various Indo-European peoples dominated the Central Asia region stretching from Northern Caucasus and Volga basin to the Northern fringes of Indian subcontinent which historically began at Bactria,Tarim Basin and Sogdia. The region is exploding with flourishing diverse groups of Indo-European peoples almost all looking almost like Central and Northwest Europeans. Satem speaking Scythians(including Sarmatians),Western Iranian peoples,Original Indo-Aryans,Sogdians and unclassified Iranian and Indo-Aryan peoples speaking Avestan and it's twin Proto-Indo-Aryan language are also in vast regions of Central Asia,etc,Massagatae and the Centum speaking Celtic or Germanic looking Indo-Europeans,the Tocharians. They first build smaller city states like the league of Latins in Khwarazem,Transoxania,Green regions of Iran,Sogdia,Bactria,Gandhara and surroundings as far as the Iranian peoples are concerned and Tocharians build such city states in Tarim Basin,parts of today's Kyrgyzstan,greener parts of Xinjiang till Urumqi and Khotan. These form a league soon after flourishing in population and culture and soon both Iranians and Tocharians unite. A religion mix of Zoroastrianism and Buddhism is the religion with advanced theories of Metaphysics and such is also the state religion. Eventually ports for trade are built in parts of Iran and India. India is colonized and the population soon becomes very large there too. Mongolia is also loosely controlled eventually annexed and colonized. Same with large parts of China if possible. Great cultural and historical centers are built in Khwarazem,Transoxania,Persia and Tarim Basin. Advanced science develops very early well with friendly interaction with all other civilizations and empires as brutal invasions of OTL are butterflied. The World becomes a brotherly,peaceful and a Green World. Religions are advanced and peaceful and are studied and practiced in all the languages. Tocharians and Eastern Iranian peoples flourish as a great civilization builders and advanced beings instead of going extinct as OTL. It is a happy timeline ever after on the Earth.