I played a BF1918 mod for BF1942 a while ago, and while it's obviously a 14 year old game, my concerns from the gameplay of that have come back after thinking of this mod I used to play.
Weapons: The weapons of The Great War are pretty limited to bolt action rifles, pistols, and very heavy machine guns. Some sub machine guns and the BAR were introduced towards the end of the war, but there were very limited numbers. Artillery was of course used in huge numbers, but more on that later.
Vehicles: Tanks were first introduced in 1917 at the battle of Cambrai. They were not produced in large enough numbers to have a lot of effect, and officers used to walk in front of their tanks to check the ground was suitable for them to cross, which kind of goes to show their limited capabilities and speed. The most widely used tank, the Mark IV, was armed with two 57mm guns, and could go 4mph, so they are not the Blitzkrieg Panzers we are used to seeing. Yeah, they were scary as **** because nobody knew what to do with them at first, but it's not exactly lightning warfare.
As for aircraft, bi and tri planes are really not very fast, with the Sopwith Camel achieving only 113mph top speed, and again they were only produced in limited numbers. While dogfights were quite common, bombing and intelligence gathering were aircraft's primary roles, along with artillery spotting.
Tactics: Trench. Warfare. If you know anything about WW1, you will know it was muddy, disease ridden, and downright ****ing brutal in the trenches. Long periods of waiting, getting shelled, getting gassed, getting trenchfoot, going mad, generally not nice. Then when you did get some action, you go over the top, and if you didn't get mown down by machine guns (there were 90,000 casualties on the first day of the Somme) then it was man to man, knife combat in the opposing trench. There was no SAS, no parachute regiment, no special forces in The Great War, so you are looking at pretty much trench to trench warfare over and over again.
TL;DR - While it's a good change from the norm, I really don't think it will make for fantastic gameplay if they want to make it historically accurate. If they don't, well, then they might as well have made one for the ****ing Napoleonic wars.
