India FATA procedures
You wrote: The company on the other hand know they can get pilots to replace them (strike breakers) within 24 hours if necessary from anywhere in the world.
This is not true. To work in India, you first need security clearance before you get to India. This takes from 6 weeks to 3 months or more in some cases.
Then after arrival in India, you must do an oral exam at the DGCA in Delhi to get your FATA. (Foreign Aircrew Temporary Authorisation). After 90 days you do the written exam.
Meanwhile, there is a mountain of paperwork, clearances etc. So getting Expats in and flying within 24 hours is not an option open to the management.