Hi Lawrence
Understood, except that leaving a column (from position #2) and entering a space insufficient for your frontage involves some sort of 'interpenetration' - leaving a column is an exemption for entering small spaces and as such means you don't have to worry about how you get into the space, hence my contrived example.
To me this raises the question of why wasn't there a wider audience for play testing???
Regards
Andrew
Consider a column of 3 blades.
Now take out the second rank blade and put it beside the column.
Now slide it back in to its original position.
Consider a line of two blades. Now move one blade sideways half a base.
Now take a third blade behind the line but facing 45 degrees left.
Advance this blade so its front corner enters tha half-base wide gap.
IMO these are examples of what is meant by "entering a space insufficient for its own frontage."
No interpenetration is involved in either case.
I'm not sure why elements expanding from column need a specific permission to do this, but it might be to allow them to deploy into the second rank of a three deep formation.
As for play testing, I suspect it was because most of the potential play testers still played DBM and it is very difficult to play both DBM and DBMM without getting confused. So they mostly decided to avoid confusion and didn't play test it. This particularly applies to keen competition players who are the ones that read rules most closely, stretch wording to its limit of interpretation and like everything to be clear and consistent.