I've heard the idea that during WWI Germany was basically "Shackled to a corpse" in the form of it's allies. How much of that was true, and how much German propoganda? Had WWI somehow occured with the same forces arrayed against just Germany, could they have done any better?
Germany was shackled to the corpse of the Hapsburg Empire. It was horrendously true.
Between the Battles in Galicia and on the Serbian Frontier, the Austro-Hungarian Army suffered the loss of one quarter of it's rank and file, and half of it's officer corps; total casualties by the end of the year were over 1 million. By this time, the fortress of Przemysl was under siege, to fall in early 1915, and the Russians were forcing their way through the Carpathians.
The Austro-Hungarian counter-offensives in the Carpathians cost the army 800 000 casualties, for minimal or no gains. With the arrival of the German 11th Army under August von Mackensen, a grim pattern was set: the Austro-Hungarian Army would be incapable of carrying out operations effectively without German support.
In June, 1916, the Russians launched the Brusilov Offensive; in the first 12 days, 280 000 Austro-Hungarian troops became casualties, and by September the Army had suffered 1 million casualties, including 350 000 Hapsburg troops taken prisoner. The frontline had been pushed back to the Carpathians, and what was more, the Eastern Front now effectively came under German control. Austro-Hungarian forces would ultimately answer to a German supreme commander.
1914 gutted the Hapsburg army, the Brusilov Offensive disembowelled it. The best that can be said is that had Austria-Hungary not been present in 1914, there would have been nothing to absorb the Russian, and subsequently the Italian, Army. Without any allies, I doubt Germany would have gone to war at all.