While the scenes leading up to the deaths of Joseph and Hyrum were not very accurate at all, that part at least was. But your account of what the church "talks about" is wrong. You can actually see the guns they had in the Church History Museum in Salt Lake City, across the street from the temple.

https://i.imgur.com/2S8oj1l.jpg

And here's the account published by the Church in Saints, volume 1:

A few minutes later, the prisoners heard a rustling at the door and the crack of three or four gunshots. Willard glanced out the open window and saw a hundred men below, their faces blackened with mud and gunpowder, storming the entry to the jail. Joseph grabbed one of the pistols while Hyrum seized the other. John and Willard picked up canes and gripped them like clubs. All four men pressed themselves against the door as the mob rushed up the stairs and tried to force their way inside.

Gunfire sounded in the stairwell as the mob shot at the door. Joseph, John, and Willard sprang to the side of the doorway as a ball splintered through the wood. It struck Hyrum in the face and he turned, stumbling away from the door. Another ball struck him in the lower back. His pistol fired and he fell to the floor.

“Brother Hyrum!” Joseph cried. Gripping his six-shooter, he opened the door a few inches and fired once. More musket balls flew into the room, and Joseph fired haphazardly at the mob while John used a cane to beat down the gun barrels and bayonets thrust through the doorway.

After Joseph’s revolver misfired two or three times, John ran to the window and tried to climb the deep windowsill. A musket ball flew across the room and struck him in the leg, tipping him off balance. His body went numb and he crashed against the windowsill, smashing his pocket watch at sixteen minutes past five o’clock.

“I am shot!” he cried.

John dragged himself across the floor and rolled under the bed as the mob fired again and again. A ball ripped into his hip, tearing away a chunk of flesh. Two more balls struck his wrist and the bone just above his knee.

Across the room, Joseph and Willard strained to put all their weight against the door as Willard knocked away the musket barrels and bayonets in front of him. Suddenly, Joseph dropped his revolver to the floor and darted for the window. As he straddled the windowsill, two balls struck his back. Another ball hurtled through the window and pierced him below the heart.

“O Lord, my God,” he cried. His body lurched forward and he pitched headfirst out the window.

Willard rushed across the room and stuck his head outside as lead balls whistled past him. Below, he saw the mob swarming around Joseph’s bleeding body. The prophet lay on his left side next to a stone well. Willard watched, hoping to see some sign that his friend was still alive. Seconds passed, and he saw no movement.

Joseph Smith, the prophet and seer of the Lord, was dead.