Disputes in command happens all the time. But in PLA, the disputes can really paralyze large units becouse it can take place by two equal leaders. In west the disputes cannot stall the commanders decission in the minute pasis, it can cost him his rank and freedom afterwards, but it cannot stall the units operationality.
But The commisar takes lot of the work that in western is traditionally been under the seccond-in-command, or under what we called, unit officer...or sort of Quarter master.
So in that sense the system is pretty close to what army unit command hierarchy should be. The proplems roses from the fact that Commisar doesent just manage these things, but leads the unit in this field. He has the final word in these subjects and despite their sound like unimportant rear area issues, the work load of the Commisar actually covers the most crucial features that comes to units fighting capacity. In the wilderness, (aka combat enverioment) these things are still managed by the commisar, and expecially in the wild, they should really be under the unit commanders juristiction so that he can properly lead his unit be aware of its internal situation and have tools to improve it. Military unit leadership isent just knowing the rigth tactics and strategies, its about managing punch of soldiers. In PRC this is divided so that the soldier leads only the military side and political party watch dog leads all other aspects.
That relationship between the commisar and unit military leader consist from the start a really bad drift and friction and the main consern of the entire system is its inflexibility. In west, when unit commander has an innovative idea, its up to his own mind and persona, wheter the unit conducts his idea, but in PLA it needs to have both Commisar and unit leader having to agree that wheter that idea is good or not.
And innovativeness, innovativeness or lack of it is propaply one of the most important single thing that determens succes in military operations. In Spanish Civil war and In 1939 Finnish-russian war, the main reason for communist forces failure was that the military units, companies up to divisions lacked the flexiility to adapt into situations that werent anticipated by the doctrines and "scientifical war fare". This along with the units lack of innovativenes to exploid sudden favorable situation lead into cathastrophic consequences. This inflexibility wasent coused just from the commisar system, but the commisars, wheter they intervented into the decission making or not were big factor in it.
What many of you tryes to ignore is the political guard function of the commisars and that systems main effect to any unit is that the leader has to be obeyable to the agreeded doctrines and strategies becouse any sort of private venturism can be seen by the commisars as "treason" like Fishead it so arubtly stated.
In todays PLA there still remains strict doctrines and this inflexible chain of command to assure that the doctrines are followed by the book. We can all lead conclusions of how such army can manage in the modern battle field where situation awareness is even more crucial and decive commands are to be given in the blink of an eye, not after party comitee meating has agreeded that such action would be Ok to do.
Military leadership comes in rootlevel down to individual skills, democracy and split responsibility neglects this factor and takes the focus out of it.