weight distribution

[ynze]

Hello,
for most postures in our form we have a totally different weight distribution then other taiji forms. Either almost full on rear or front leg.
But I'm a little lost as far as single whip and elbow/shoulder strike is concerned. When I do these I am around 70% front and 30% rear. Up until half of 2nd duan that's the only time this happens.

Is this distribution correct? The smaller my stance the more I can keep my weight on the rear leg. But looking at pictures of master Wang or laoshi they have a larger stance.
Am I missing something??