Do you really believe India would have united peacefully without the British? Every time the Subcontinent was united was due to someone conquering it... such as the Gupta EMPIRE, the Mughal EMPIRE or the Mauryan EMPIRE. India has been no stranger to war with or without the British.
Do you really believe that British united India peacefully?
Bringing numerous Kingdoms under an Imperial throne has never been compeltely free of wars. And again .. the British didn't unite India.
They ruled over various parts of Indian terriroty via one administrative unit. What united India was the common struggle against the British that evolved into the 19th and 20th century Indian nationalism. You are mixing Territory with Nation.
Ancient Imperials weren't genocidal. The Mauryans didn't persecute the people like the British or Mughals did. Guptas didn't persecute the people like the British or Mughals did.
Above all, British were completely foreign in India and had no rights to interfere in Indian administration. British don't have any moral high grounds over Mauryans or Guptas.
Read the Chinese travellers accounts of India to know what Indian martial traditions were and how Kshatriyas of various Kingdoms fought battles.
Perhaps an Indian account would be called biased.
As far as Mughals are concerned, the medieval history of India is full of the blood that is on their shoulders. All you have to do is pick the books up and read.
Regards,
Virendra