Complex sentence: In mid-March, Falkenhayn had reminded the 5th Army to use tactics intended to conserve infantry, after the corps commanders had been allowed discretion to choose between the cautious step-by-step tactics desired by Falkenhayn and maximum efforts, intended to obtain quick results.
Split into simpler sentences: In mid-March, Falkenhayn had reminded the 5th Army to use tactics intended to conserve infantry. The corps commanders had been allowed discretion to choose between the cautious step-by-step tactics, desired by Falkenhayn, and maximum efforts to obtain quick results.