Difference between group moves and column moves

[Craig]

I found the rule sections on group moves and column moves a little fiddly to read as they have many of the same rules with just a few differences.

From what I can see the differences between group moves and column moves is that:
* columns can be 1 unit wide only
* columns don't suffer any ill effects from moving through difficult terrain
* units in column wheel at the same point

If this is the only difference then would it be more parsimonious to just talk about group moves and have a section on column moves as a specific case? This would then avoid repeating the rules with minor variation for group moves and column moves.