The first is an interesting article but the author's conclusions are not consistent with some of the material in the article. The author has recognised and described the range of close combat melée weapons that were used in trench raids. The cavalry sword and lance were the equivalent of this type of weapon. They enabled cavalry to engage the enemy at close quarters, when rifles or carbines would not have been appropriate. Note that calvary were trained in the use of the bayonet for close quarters fighting when dismounted. To this extent, the sword and lance were no different fundamentally from the mace, knuckleduster, bayonet, or any other weapon, except that they could be wielded in close quarters from horseback.
An issue was not the close quarters weapons per se but how the users were enabled to get close enough to use them. For trench raiders, darkness (to limit line of sight) and barrages (to suppress the enemy) were used to enable the raiders to get into close contact. Barrages were not always used, in which case darkness can also be thought of as having a suppression function also – reducing the numbers of enemy available to spot and to engage the raiders during their crossing of No Man's Land and entering the enemy trenches. Cavalry were trained in applying suppressive fire before attempting to get to and engage the enemy with the sword or lance. In this context, both were weapons of their time. No Napoleonic cavalry squadron had the ability to use a second squadron and an MG team, along with quick-firing horse-drawn artillery, to get its riders onto a suppressed enemy.
The second issue is that close quarters cavalry combat was not the major function of cavalry, something that was recognised even before the war broke out. Deep reconnaissance and counter-reconnaissance were key roles, both of which required the capacity to engage enemy calvary at distance (with rifle and carbine fire) and at close quarters. Skirmishes were not infrequent (note the description of the British action at Casteau in the second article), particularly in the terrain of the Ardennes and northern France.
The other key role was exploitation. Again, this would involve minor skirmishes as large engagements against static enemy meant that a breakthrough had not been achieved.
It should be noted that Light Horsemen in Palestine used the bayonet from the saddle too, as a thrusting weapon when the sword was not available.
Robert