What's the difference?

What's the difference?

There is a מחלוקת רש"י ור"ת how to place the Parshiyos in the Tefillin and the Mezuzah on the doorpost.

 vertical or horizontal.

To be יוצא ידי שניהם the Mezuzah is placed at an

angle.

To be יוצא ידי שניהם the Medakdekim wear both 

Rashi & RABEINU Tam Tefillin.

1) Why don't the Medakdekim place two Mezuzos on

each door post one vertical and one horizontal to

be יוצא ידי שניהם?

2) Why don't we place the Parshiyos in the Tefillin

at an angle to be יוצא ידי שניהם,?