In view of the failure of anti-German forces at making headway against a well-entrenched enemy equipped with machine guns, is there another strategy the allies could have pursued?
Well, they could develop a mobile gun platform, maybe armoured against enemy machine guns, and call it a 'landship'. Oh, they did do that, but called it a tank named 'Little Willie'!
"It seems that the invention of tanks was the great turning point of the war."
It certainly was and tactics had to constantly change quick to deal with them. Even the defensive effectiveness of the positioning of the state-of-art Maginot Line was soon outdated by the capabilities of next generation of tanks / tank warfare during WW2.