Bearing in mind that the training system is imparting the skills and knowledge to be used for the rest of the aviator's career why should we over-complicate it by having one set of rules during training followed by a new set when that training is put into practise?
You can certainly teach the handling skills for any position in the formation despite the number attached to your callsign. Again, the students generally cope very well with this, as do most creamies and FJ mates who've returned from the front line. Its not hard to understand what 'reverse vic' means.
Of course the student needs to see all formation positions and as many situations as possible but don't confuse this with a desire for No2 to always sit on the right - No2 can go wherever the leader decides! Let's make the training relevant to the end task!