There is a school of thought who is convinced that the Sepoys were bound to fail. But again there is nothing that is inevitable in history. Before 11 May 1857 no one could have believed that one regiment composed of Ranghars and Hindustani Pathan troopers could seize Delhi and wind up the EEIC hold on India for good! No one before 10 May 1857 would have believed that “2028” European soldiers at Meerut could not effectively disarm “2057” Native Sepoys. The layman reader should not underestimate what “2028” Europeans meant in India in 1857. the EEIC forces consisting of some 2300 native sepoys and just about 500 European troops from HM 22 Foot captured Sind in 1843550! In September 1842 General Nott using just about two European infantry battalions and some seven Bengal and Bombay Army native units captured Kabul the capital of Afghanistan.
Those who understand Indo Pak military history of 19th Century were thus naturally surprised the way the British at Meerut behaved. Even the 3rd Light Cavalry troopers were surprised to witness such masterly inaction on part of the European troops at Meerut. It was only when they were convinced that the Europeans had sunk into absolute inertia and inactivity that they regained enough resolution to move towards Delhi. The sepoys had a fair chance of success till September 1857. Had they destroyed the British force at Delhi they would have gained moral ascendancy and the British position may have become more critical. We have already seen that the British position at Delhi was never comfortable till the city was finally captured.
The fact that the rebellion was confined to certain areas still does not dismiss it as a mutiny, revolutions never breakout simultaneously to cover whole of a country. The French Revolution of 1789, 1830 and 1848 was largely the work of the Paris mob but were called the French Revolution. The Bolshevik Revolution of 1917 was initially confined to Petersburg but ultimately by 1921 the Bolsheviks were controlling whole of Russia.
The only real hope for the sepoys lay in simultaneous uprising all over India. But this was too ambitious a possibility and since no deliberate conspiracy seems to have been at work this was a very utopian and nearly impossible possibility.
Intervention by Afghanistan and Nepal may have seriously tilted the balance against the EEIC. In NWFP at least there would have been a general uprising in case Afghans had decided to invade India. But Nott and Ochterlony had taught such a lesson to Afghanistan in 1842 and Nepal in 1816 that both the countries rulers were too keen to please the EEIC to the best of their ability!. India was not a country and it was this on ground reality which made the British task very simple. The rebellion remained regionalised and the people of the sub continent as a whole lost a very good opportunity to become independent.