This is not a reference to "current events" but to Fall Blau the 1942 attack on the southern Soviet Union by Army Group South. The campaign started smoothly enough, with the approach to (and capture of Vornezh) by Herman Hoth's 4th Panzer Army. Then Paulus' Sixth Army followed with an advance in the Don bend. So far so good.
The two armies mentioned were later grouped into Army Group B. At the extreme south, Army Group A captured Rostov-on-the Don, crossed the river, headed south for the Maikop oil fields, and found its way blocked, not by the Soviets, but by Hoth's 4th Panzer army, which had been ordered by Hitler to support the thrust to the Caucasus. Moreover, Hoth's troops would not yield the right of way to Army Group A, creating a massive snarl at a time when fuel was a scarce commodity.
How did this come about? Even if Hitler wanted Hoth (and the 4th Roumanian army) to support Army Group A, why didn't he subordinate Hoth to Army Group A instead of letting him operate independently? And why would Hoth be allowed move in the same direction, south, and ultimately over the same roads as Army Group A instead of e.g. "east then south," like the 4th Roumanian Army? (This would have put Hoth parallel to Army Group A, protecting its weak flank and would have created a broader front that would have improved the Germans' chances of success.)
(Note: I am not asking why Hitler attacked in the south or why he sent Hoth's army to support Army Group A. The question is why was the tactical execution of his directives so poor, resulting in a major duplication of effort.)