The army reforms of Sher Shah aimed to strengthen and modernize the military. Option 1, keeping a large army at the center, was indeed part of these reforms. This involved maintaining a significant military presence in the capital to ensure stability and protect against potential threats.

Option 2, the introduction of swiftly moving artillery, is the correct answer to the question. This means that it did not constitute part of Sher Shah`s army reforms. While Sher Shah did focus on improving his army`s mobility and firepower, there is no mention of specifically introducing swiftly moving artillery as part of his reforms.

Option 3, cash payment to soldiers, was a key component of Sher Shah`s reforms. By implementing this system, soldiers were paid in cash, which increased their morale and loyalty, and ensured regular payment without the delay and issues associated with supplying goods or commodities.

Option 4, the introduction of the practice of branding horses, was also a part of Sher Shah`s army reforms. Branding horses was done to establish ownership, prevent theft, and ensure the availability of trained horses for the army.

In conclusion, while options 1, 3, and 4 constituted part of the army reforms of Sher Shah, option 2, the introduction of swiftly moving artillery, did not.