If you drop the tremor totems staggered, it should reduce it somewhat from 4 seconds

Sham1 - /castsequence tremor totem,,,
Sham2 - /castsequence ,tremor totem,,
Sham3 - /castsequence ,,tremor totem,
Sham4 - /castsequence ,,,,tremor totem

or

Sham1 - /castsequence tremor totem,<different totem>,<different totem>,<different totem>
Sham2 - /castsequence <different totem>,tremor totem,<different totem>,<different totem>
Sham3 - /castsequence <different totem>,<different totem>,tremor totem,<different totem>
Sham4 - /castsequence <different totem>,<different totem>,<different totem>,tremor totem

The fear will still hit, but it might only last 1-2 seconds