I think 40 aircraft is good enough for MK1, cause we have to accept that MK1 is atleast 5-6 years late if not more then that.
The 40 aircraft are a token number just to get the IAF started and familiarized with the type. Otherwise the Mk.1 is woefully lacking in meeting the IAF's requirements. Hopefully the Mk.2 will address these shortcomings quickly.. but will it be relevant to the IAF's Air Staff requirements when it arrives is something to be seen.