I think you may be arguing what is theoretically possible with what is practically possible under battlefield conditions, whereas I am pointing out the practical rate of fire. I am well aware that revolvers and bolt-action rifles can be fired as fast as automatic weapons given proper technique and concentration. I have also read accounts of Japanese archery masters exceeding 20 shots per minute and maintaining that rate of fire for hours, let alone minutes. I have even fired such weapons myself and see no reason why such records should be questioned. Nevertheless, these impressive totals drop drastically in combat situations where the enemy is shooting back or charging at you, even for hardened professionals. Unfortunately, I have never been in a combat situation with a non-automatic weapon, so I have to trust historical accounts when it comes to evaluating rates of fire. Historical accounts are often riddled with errors (casualty figures spring to mind here), but 12-15 rounds per minute seems to be the consensus regarding the remarkable rate of fire displayed in 1914 by the BEF during the early battles, set against a somewhat slower 8-10 rounds for green troops. This was enough to force trench warfare. In fact, a much slower rate of fire with rifle muskets was enough to force trench warfare and open formations during the American Civil War (I don't think anyone can argue for 30 rounds a minute with a musket). We see nothing like this for longbows (or crossbows), even though supposedly they also penetrated all armor, shot just as far, and twice or thrice as fast. Something is being exaggerated here.

I refer to the SMLE as a carbine. This is not entirely accurate, since I think there was a shorter weapon officially designated as the carbine, but I think it was the general trend in infantry rifles to get shorter around this time (while the bayonets get correspondingly longer).