Alignment of people's names


When people's names are listed with both sides aligned (either in horizontal
or vertical writing), for example, in the ending scroll of a movie, there is a
seemingly complicated rule (to me).

When the length of the name (family plus given) is not three characters, the
positioning is such that the characters are distributed evenly, without
particular segmentation between the family and the given name parts:

> X* = family name, Y* = given name
>
> X Y  
>  X Y Y Y  
>  X X Y Y  
>  X X X Y  
>  X Y Y Y Y  
>  X X Y Y Y  
>  X X X Y Y  
>  X X X X Y

However, when the length is three, it seems as if a space character is
inserted between the family and the given parts and the positioning is done
counting in the space character, like this:

> X Y Y  
>  X X Y

Considering the rules for the other cases, I would rather expect:

> X Y Y  
>  X X Y

Why is it like as is? Is there a rule behind that makes the length-3 cases
non-exceptional, or is there a reason why length-3 is exceptional, or, is it
just due to inconsistency/stupidity of whomever started it?

**Edit**

Or to see it from the other side, it is natural that a space be inserted in
between the family and the given names (as Dave points out in the comment).
Then, why are the cases other than length-3 (except the length-2 case, which
can be interpreted in either way) not having a space? I would rather expect:

> X Y Y Y  
>  X X Y Y  
>  X X X Y

and so on.

**Edit** These are links to some pictures that describe the situation (with
some variations):

  * [picture](http://static.panoramio.com/photos/original/59902844.jpg)
  * [picture](http://static.panoramio.com/photos/original/62534614.jpg)
  * [picture](http://blogimg.goo.ne.jp/user_image/0e/fa/4443ef48816f46ec3daedcb65cb1681c.jpg)
  * [picture](http://dictionary.sanseido-publ.co.jp/dicts/encyc/concise_name_wd/img/gaijin_tyosa.jpg)
  * [picture](http://dictionary.sanseido-publ.co.jp/dicts/encyc/edo_study/img/edo_tokyo_sinso_sippitu.jpg)




I believe the rule you are looking for is called `人名字取り`. `5字取り` is the most
commonly used for the closing credits in movies. What this means, is
everything is aligned based on 5 characters.

Here is an image for reference
([link](http://www.ayatoweb.com/tv_design/tvd83.html)).

![enter image description here](https://i.stack.imgur.com/kyDCv.gif)

I found this [other reference](http://www.yut.co.jp/ht_jidori.htm) which has a
few more patterns (posted below). If I'm understanding the question correctly,
`5字取り` or `7字取り` pattern B seems similar to what sawa is explaining. However,
since there are many different patterns, it might be impossible to find an
exact match.

![enter image description here](https://i.stack.imgur.com/jvbO4.gif)

