In Nanoha's case, it definitely wasn't flattering, but:
Duties as Instructor
1a) The canon shows effort.
1b) The canon shows no development in the level of tactical and moral-psychological training, but substantial improvements in combat skill equivalent to at least one full mage rank, as verified by enemy evaluation, results of mock combat and the real combat, which while sloppy (due to the lack of tactical and moral-psychological training) did end with their victory due to a mixture of luck and combat skill.
1c) The canon has described her experience, which implies that Nanoha probably has little experience (and thus readiness) to deal with her expanded responsibilities of Tactical (in the English, not Midchildran definition) and Moral-Psychological trainer.
1d) The conclusion is that Nanoha, pushed into a role that she was not properly qualified for, executed her task in the only way she knew how. She proved to be reasonably effective in the task she was experienced in, and the overall product, while hardly a success, proved marginally adequate to the task.

Duties as Commander
2a) Her daily responsibility to ensure the readiness of her subunit is arguably untenable due to Factor 1C and her extra duty as Instructor (which seems to take up most of her time). Fate is presumably in a similar situation due to her extra duty as Investigator.
2b) Her combat responsibility of troop control is complicated by both Factor 1C and the unrealistic unit organization which bears no resemblance to Operational reality, resulting in the near impossibility of positive troop control.
2c) Under the circumstances, the Subunit Commanders' (Fate and Nanoha) decision, after the first battle of the unit (Ep5), to create a new ad hoc ground squad organization and delegate control to the initiative of senior, most tactically competent member of their ground units for the duration of combat is probably correct.

Combatant
3a) In Ep5, Nanoha operated in accordance to the Concept of Battle of the Unit Commander commanding from the Command Post.
3b) In Ep7, Nanoha operated under the Direct Control of the Unit Commander commanding from a Command Observation Point.
3c) In Ep9, Nanoha operated in accordance to the Decision (made after conferring with staff) of the Unit Commander commanding from the Command Post.
3d) In Ep12, Nanoha operated under the Direct Control of the Unit Commander from a Command Observation Point.
3e) In Ep16-17, Nanoha operated under the failure of Troop Control due to the effective negligence of the troop control system by the Unit Commander.
3f) In Ep21-26, Nanoha operated under the supervision of the Unit Commander commanding from the Forward Command Point. The poor decision to split up is at the strong insistence of her subunit's deputy commander, in accordance to the Concept of Battle of her Unit Commander (as well as what passes for TSAB Doctrine), and not overriden by the supervising Unit Commander.

Responsibility
1a) The responsibility for selecting Nanoha for the job of Instructor, despite the requirements and reality of Factor 1C, is the responsibility of the Unit Commander, who apparently was given wide powers to select the optimum personnel.
1b) Alternatively, the selection of Nanoha for the job of Instructor may be adequate if the Unit Commander spends some time on Commander's and Tactical Training to complement the instructor's limitations. This was not done, perhaps because the Unit Commander feels it un-necessary or worse, perhaps because she lacks the ability and/or confidence to do so.
1c) The cause is likely due to assuming Tactics (戦術) = Martial/Combat Skills (戦技), an assumption probably prompted by the Midchildran lexicon (see Nanoha's ID card and compare to Japanese), but nevertheless ignorant and indicative of a poor level of professional developmen on the part of the Unit Commander.

2) The responsibility for 2A (overtasking) 2B (unrealistic unit organization), lies with the Unit Commander. As the person who proposed the very concept of the unit, she has wide influence in the organization of the unit to avoid such problems. This shows a poor understanding of the workloads involved in the various duties, or the capabilities and proper employment of various units.

3) I suppose the responsibility in all of 3 is obvious.