It recently 'struck me' that - assuming angels are beings with free will, and are indeed of the same 'kind' as Men and Jesus Christ (as Mormons believe) - there is no reason to assume that angels are perfect or infallible; and, on the contrary, every reason to believe that they are learning, progressing by trial and error - as we are.
Angels are, indeed, engaged in a process of education by experience - but approaching this educational process from the top-down (rather than from the bottom-up, as are we).
I tend to assume that, because they reside in Heaven in close contact and communication with the Godhead, angels are always well-motivated, always doing their best, always Good - but I suppose that their knowledge and abilities and foresight are all limited.
They must therefore make mistakes and perform their jobs (to some extent) sub-optimally.
So, on this basis, real life angels may be much like that most famous of fantasy angels: Gandalf.
Note: this insight owes much to the ideas of William Arkle, for example: Discovering your soul's purpose at http://www.wessexresearchgroup.org/digital_08.html