Many have criticized the WW1 generals for the trench warfare tactics on the western front, specifically frontal assault "wave" tactics. My question is: What alternative was there? "Not fighting" is not an alternative, as a commander who did so would be replaced. There was no room for maneuver. Until 1917, the Allies did not have a sufficient number of HE shells or trained gunners to effectively utilize a creeping barrage or hurricane bombardment on a large scale. Tactics were constantly changing. There was no effective means of battlefield communications, so everthing needed to be pre-planned at staff level HQ and carried out on a timetable because it was literally impossible to know what was going on.
So I ask, what other "tactics" were available to WW1 generals prior to 1917 than those that were utilized?
Until 1917, the Allies did not have a sufficient number of HE shells or trained gunners to effectively utilize a creeping barrage or hurricane bombardment on a large scale
Not true; the French made extensive use of creeping barrages during the Somme campaign, as did the British. Both the Germans and the French made use of crushing levels of firepower at Verdun (in the German and French case) and on the Somme (in the French case).
From c. May 1915 onwards, the French were already moving towards and effective operational method, with corresponding tactics. Andre Laffargue's The Attack in Trench Warfare was widely distributed following the 1915 Second Artois Offensive, and by 1916 the infantry tactics it recommended were already being implemented. Infantry moved in small units, spread out with LMGs, rifle grenade launchers, mortars and 37mm infantry guns to support their advance. As an operational method, so-called 'Methodical Battle' became the name of the game, with artillery range limiting advances on the ground, and copious use of artillery to support the infantry. As Petain put it, "the Artillery Conquers, the Infantry Occupies".
German developments were similar in the use of artillery, as the crushing weight of German artillery at Verdun demonstrates. In infantry Tactics, whereas the French focused on disseminating tactical developments among the whole ranks, the Germans focused on battalion-sized units, eventually called 'Sturm Abteilungen'' or 'Assault/storm detachments'. These evolved into the Stosstruppen units.
The British army had things more difficult, as it had little real experience in major operations, and was constantly expanding until the end of 1916, while also possessing a smaller corps of veteran soldiers and officers than either the Germans or the French. However, by the time the Somme Campaign had reached it's climax in September 1916, the British were on the way to a similar tactical revolution; The Battles of Flers-Courcelettes and Thiepval in September 1916 are cases in point. By 1917, the BEF was a formidable force, which would only grow more so before the war's end.