My teacher would argue with your teacher. ...
In my experience it's only the stundents who argue. ...
The teachers mostly don't need to ...
... Stand in hamni and have someone push on the middle of your chest, and then on your upper back. ...
Do you also do pushing from the side?
Why do you think hanmi has to be "stable" to the rear? + What is best for being pushed from / for pushing yourself to the front?
Do you try to move from hanmi having your axis on different positions? Do you feell differences?
Do you investigate the connection / the "way" back leg -> center / tanden -> front leg and backward? And if so: Does it feel different where you have your leg?