What you seek is simply what you get
First off, this might well be actor Akshay Kumar's finest performance ever. And this has much to do with an earthy, true-blue, proud Punjabiness that he exudes in his natural persona that translates so seamlessly on to the big screen; him fitting into the get-up like a glove, as Havildar Ishar Singh, a die-hard, hatta-katta soldier with a sharp disc on his huge turban, belonging to what the British deemed the 'martial race'—born to fight and protect, for community, and honour.
And that's tall compliment for a superstar, currently at the brightest phase of his career, who for years since he made his debut was condescendingly dismissed as woodwork—chiefly for the kind of work he starred in, of course.
Kumar, lesser known as Rajiv Bhatia, over the past few years, has upped his game to a point that you can't tell one character of his from the next (his last outing was as the iPhone sensation, Pakshi Rajan, in 2.0), naturally generating curiosity in ways that Aamir Khan has been capable of. Surely there are other contenders too, but hardly as prolific.
That said, you know where this film is coming from: 1897, Battle of Saragarhi, fought between Sikh soldiers under the British, and Afghan/Pashtun tribesmen from North West Frontier Province, or what's now the Khyber Pakhtunkhwa in Pakistan.
What's more important for the viewer to figure/gauge/understand is where this film is going—mainly towards mainstream, mass-belt audiences in Punjab/North, naturally inclined towards manic action films, exhibiting bravado of a community that has enough history to prove for it.
The director is most loved for massive Punjabi hits like Jatt And Juliet, and its sequel. Frankly, Sunny Deol is the only other actor I can think of who could so easily have pulled off this rustic 'gadarness' with gusto. The younger lot doesn't quite cut it in that sense. And Kumar has a cred that precedes his presence. Here he does to Sikh pride through dialogue-heavy, relatively over-the-top, period action-drama, what he attempted in Singh Is Kinng (2008) through comedy, with considerable success.
The key is the story of course. But the downer, the script/screenplay, probably naturally flows from there as well. For how do you spin off an entire feature from what's essentially a merciless, brutal battle between two groups, where the side you're on (the Sikhs) has no stake in the system?
They're minor soldiers. Their bravado is deliriously captivating, yes. You can see it. You can feel it. But the battle can't be the whole film. Well it is already half of it, with scenes leading up to the big moment essentially checking off boxes for issues that the film wants to perfunctorily highlight: caste, religion, colonialism, slavery. What you seek is simply what you get; no more, no less.
At the heart of this pic is the fact that 21 soldiers of a Sikh regiment held fort, carried on what was self-admittedly a suicide mission, against an army of over 10,000 tribesmen attacking them one fine day. Could this be a case-study on tactical warfare? How else did the Sikhs survive even more than a second? Or were the Afghans/Pashtun soldiers completely daft to suffer huge casualties still? Was there unlimited ammo at Saragarhi, or was the opposing side marching in with seriously primitive weapons?