As I understand it the difference of the MK1A and MK1 is primarily in the internal systems, so the current production line can be leveraged with minimal changes, so long as all the testing have been done and verified.
The number of fighters needed isn’t dependent on what the rest of the world has but what the requirements of the IAF says and according to them even with the additional 83 there is still the shortfall of an additional 114, furthermore, there will be other older aircraft slated for decommissioning and will require replacements in the coming 5-10 years on top of the MIG 21s and MIG 27s that the order is meant to replace...
Finally MWF is still on the drawing board... with the expected first flight of 2023... after that who knows when production will actually begin, there is also the consideration of the Su-30MK1’s production coming to an end, while the Tejas is not the same class/role of aircraft, the situation that India is in right now, any additional combat aircraft is a plus... MWF represent much greater changes... there are also not-so-minor airframe changes in addition to internal system changes... with the track record of the Tejas program so far we might not see the MWF anytime soon after the first flight and thus the plugging will still need to be done anyway... at the very least the MK1A is currently considered an acceptable aircraft...
