Pashtuns were not invincible as some people claim and wants everyone to believe.
Read about Maharaja Ranjit Singh for details.
The invincibility and romantic notion of pathans is quite recent, interestingly promoted by mostly non-pashtuns. The reputation was of resistance and stubborness. Thats what sikh forces faced in kasur, multan, kashmir, hazara, peshawer, bannu etc. Pathans were certainly not invincible superman,they were disorganized and disunited fools, but brave and stuborn fools. Sikhs had to keep the best part of their army in deal with contineous uprisings, turbulence by pathans. Even for extraction of tributes and taxes, sikhs had to fight battles with tribes.
Why ranjeet singh emerged as truimphant against pathans?. Because the afghan rulers were busy in long civil war and tribes of frontier had not artillary and had poor weapons. It was certain that european trained and well desciplined sikh army with heavy artillary support would defeat "horde" of any tribe. The only proper battle was fought in attock in which regular army of afghans from kabul was defeated. Kasur and multan were bound to fall, they were like islands in hostile sea. In kashmir, ranjeet singh failed to capture kashmir in first two attempts, a golden oppurtunity became available to them, when he was informed by kashmiri pandit, a minister of afghans that governor has rushed to kabul with bulk of his army on hearing about murder of his bro and has left charge of kashmir with his young inexperienced bro, with only 4 thousands troops.
Attock was already fallen so when kashmir fell, hazara automatically went into hands of sikhs. Governor of peshawer agreed to pay tribute when he saw pashtun tribesmen defeated at nowshera in 1823, later it was annexed it 1834.
Mankera fell in 1821 and ranjeet singh himself led the expedition, he was aided by fateh khan tiwana, a punjabi muslim. Potohari muslims and sial-jats sided with sikhs against afghans, it was clear display of punjabi-pathan divide and prefrence for fellow punjabi-sikhs.