It didn’t say how many days the battle went, but these guys are pikers compared to two day of the battle of Shiloh and it was fought with cannon, muskets and muzzle loading rifles.
Union casualties were 13,047 (1,754 killed, 8,408 wounded, and 2,885 missing); Grant’s army bore the brunt of the fighting over the two days, with casualties of 1,513 killed, 6,601 wounded, and 2,830 missing or captured. Confederate casualties were 10,699 (1,728 killed, 8,012 wounded, and 959 missing or captured).
This total of 23,746 men represented more than the American battle-related casualties of the American Revolutionary War, the War of 1812, and the Mexican-American War combined
But there were more than 100,000 men involved at Shiloh.
The battles of the Syrian-Iraqi-ISIS war involve at most a few thousand on either side. The casualty RATE of those involved could indeed be very high.