I'm not quite sure what you mean by "efficiency" Bart.
I mean (and I understand all this hasn't got the pretention of being 'objective'): "efficient" as in direct and to the point, without any unneccesarily long intro or repetitions in general, but which still stands out for its melodic and structural wealth.
After being made to get used to long (7+ minutes) and unfortunately often bloated tracks that Maiden had got the listeners accustomed to on a very frequent basis since
The X Factor (although the "model" might predate this album: "No Prayer...", "Afraid to Shoot Strangers"), a tendency culminating in what is to me the least good post-reunion album,
A Matter of Life and Death, I like the freshness of "Tears of a Clown", despite its thematic darkness.
In other words, one reason I like this song a lot is that it seems to take the opposing view of songs such as "These Colours Don't Run", "Brighter than a Thousand Suns" and especially "For the Greater Good of God" (or "No More Lies" on the previous album), which I still "like" - I wouldn't be here otherwise - but which I tend to find a bit redundant and uninspired compared to other (and not necessarily older) songs.
I think the place of the song on the album and the latter's general track order also has to do with how each song "functions" - a bit like in a concert setlist - and I think Maiden has not made two punchy, direct AND well-written songs follow one another for a long time, until at least the first two tracks of
The Final Frontier, which in my view was significantly more pleasant than
AMOLAD, though not perfect either. My problem with
AMOLAD is that I find it quite difficult to listen to in one stretch, given the repetition of demanding lengths and structures, even though I think there are excellent moments on it (post-chorus of "BTASS", intro of "BBreeg", instrumental part of the "The Longest Day", Smith's attack on "Lord of Light", acceleration in the last part of "The Legacy"...)
To get back to "Tears of a Clown", I am very pleased it made the setlist but it seems it would have functioned better later in the show, although I understand that putting this "breather" here (in terms of a tempo) is a choice that has more to do with the musicians' stamina (the same was done with the also slower "Coming Home" on the previous album tour)
, thus allowing them to recuperate after the first 20-30 minutes of the show, than in a crowd-pleasing capacity. As another user rightly pointed earlier in the thread, the musicians of Iron Maiden play for themselves (especially now they are in or approach their sixties) as for the audience.