William,
I appreciate your problem, trying to justify a rule from a posting on a web site and not even a posting from the author of the rules must have been difficult.
If it is questioned in the future I would use the rules, not a posting on a forum to justify your decision The rule, whilst not being crystal clear is correct as written.
Point out to the player that the line up as an overlap must not be taken in isolation but it is part of a sentence. The sentence is telling you what options you have when you contact an enemy front edge with your front edge.
However, I do think it needs to be re-written at the earliest opportunity.
Chris
PS, Why do my ?speech marks? look like question marks?