Believe it or not, yes even in India there's a sane reason for the extensive medical evaluation during one's assessment in Bombay.
Around October 2010 Indian Pilots won the battle in court, requiring all expats flying with FATAs must submit to the Indian Medical, which is conducted by the Indian Air Force.
The first group of expats submitted to the medical procedure in January 2012, resulting in a fairly a high failure rate. Not only with Jet Airways crews, but with Indigo, Spice Jets, and Air India Express as well.
Expats, like locals, go to a hospital in their base town, and submit to "Pre-medical" The initial pre-medical includes Resting EKG, Stress Test, X-Ray, Full Blood work, and Ultra Sound. All reports are "Purple Stamped" by the hospital doctors and or lab technicians. Before proceeding off to Bangalore, the Company Doctors, also add their "Purple Stamp" the medical reports. Problem was, in 2012, the doctors stamped the reports, knowing that numbers were not within the parameters. Thus off the expat goes to Bangalore... doomed for problems with the Air Force Medical. If there are issues found by the medicos in then off he/she goes to the Malipar Hospital for further study, and reports on deficiencies. Then back to the Air Force Facility with the results. Thumbs up, one gets their medical certificate. Thumbs down, one gets to go home on a TMU (Temporary Medical Unfit) Status.
The bad or good news about a TMU??? time off, to resolve one's issues or seek employment elsewhere, with 70% pay for the period not to exceed, now 6 months. Other carriers sent their crews packing without TMU pay. I believe Jet Airways still provides for TMU pay, versus Spice, Air India Express, which do not.
The Indian Air Force, like China uses their own guide lines, and parameters which margins, perhaps may be narrower than other countries.
Thus the reason for the medical assessment by Jet Airways.