Alright brother.
By the way, in the first paragraph above, second line, i meant to write "tampered" - not tempered.
Do not bother 'biradar', English is not my strong point and I had understood your intent. Anyway, as promised let me explain this in a simple manner. When we talk about things like ethnicity and race, the item most important in all these discussions is language. Why? It lives with us for 24 hours a day, differentiates us from other less evolved beings and makes exchange of culture and material knowledge possible. The story starts some 7,000 years ago in Pontic steppes in modern day Russia and Kazakhastan, some people domesticate horses and practice a form of agriculture mixed with animal husbandry, learn wheel early on and have a religion where sky, fire and water are revered along with horse sacrifices. We call them PIE( Poto Indo Europeans). Starting from somewhere around 3500 BC, this group living closely starts differentiating into other groups, as this happens one original language gives birth to various new ones. These new groups while having many commonalities, have experienced mutually exclusive changes in language which means that their general culture also changes. Some 10 major groups can be identified which would remain as cohesive for next many milennia
Greek, Germanic, Balto Slavic and Indo Iranian to name most notable.
Somewhere around 2500 BC, a group becomes dominant in modern day Kazakhastan and Russian borderlands, this was eastern most branch of IEs
We call it Indo Iranian. This group is one around 2000 BC, is credited with Andronovo culture and most notably Sintasta culture, the Indo Iranians invented chariots with spoked wheel , brought a revolution in world and moved in all directions. Wait, split again takes place after this.
Indo Iranian group gets differentiated into 3 groups- Iranian, Nuristani and Indo Aryan.
So, some 4 thousand years ago, separation has taken place- Iranians are again divided into many groups like Eastern, Northern and Western. One group among Iranians reach Persia and create great empires, others remain in Bactria and Sogdiana while Scythians and Ossetians roam in area from Central Asia to Black Sea. Now, changes take place but common ancestor and common religion of all Iranaians remain the Iranian split from Indo Iranian. Hence, we have similar names and gods throughout entire Iranic zone which extended from Gansu in China to Ukraine and N Kazakhastan to Iraq border with Iran. Among these, homa, cult of fire and various IE gods remain important and we call them Iranic. Distinct from this group were Indo Aryans who instead of moving anywhere went to lands south of Hindukush, while doing this they were accompanied by some proto Eastern Iranians.
The Indo Aryans now completely distinct from Iranians develop their own Vedic religion, spread their culture and language from Hindukush to Myanmar border and Kashmir to Sri Lanka. Some East Iranians continued living in East Afghanistan along with Indo Aryans.
Indo Aryans are now in India, undergo many changes and in 21st century are second largest linguistic subgroup after sinitic.
In AF Pak area, IA remained dominant( not that they were only ones) till Islamic invasions and have a great history of their own. Gandhari was a prakrit IA language in early centuries from old IA and please note that when Gandhari came into existence, IA split was some 1000 years old. So relation between Gandhari and Iranic languages is not possible except a common ancestor in 2000 bc.
If you wish I can pick up any gandhari text , give its written form in English, translate in my native tongue and then you will see how close it is to modern day Indic ones rather than Iranic tongues. So by no means, Pashto is related to Gandhari, it is as much related as Arabic is to Aramaic and nothing more.
Pashto is east Iranic in line with Bactrian, sogdian and saka languages and when sakas arrived here, their culture and language was already very distinct.
This being reality, why can not we have better co operation? We can have after all we were one at a time, have many similarities in our original language and even genetically are related( do not go by looks, IAryans and pashtuns and Afghan tajiks indeed are related) and it is better to cooperate rather than fighting each other due to a semitic religion from deserts of Arabia dividing us.
The question is will we be able to do this? Will Tajiks and Pashtuns remember their common origin? Will both of them manage to throw off Islam? Will ancient great ritualistic religion be revived?
If all this happens, Afghanistan may be a reality as Arya Vaejo was more in Afghanistan than in Iran, but sadly I do not see any of it happening.As of now, country is set for division due to Tajik linguistic chauvinism and extreme fanaticism of Taliban.
Hope this makes some sense.