Its not just about funding or who gets the first allocation. Navy has explicatively stated that they want the OEM to make them here under MII, which is not possible unless they club the order with that of IAF. The only way to do that is through GTG or if Rafale wins both IN and IAF tender.
The "now" you're talking about is around 5 years in the future, if normal tender timelines are to be followed from RFP to trials to conclusion of negotiations. That is a problem for IAF. The only way around is if IN agrees to GTG as well and convinces the govt to the same. If IN wants to take time and evaluate both Rafale and SHornets, resulting in a win for the SHornets, its a huge blow to the IAF, who will have to wait that long for nothing. And again, the problem with MII, as now there are two different winners.
"Now" is the next 5 years. The IN's deal is expected to cost $15B. And even that is a lower estimate because they are not considering how much the actual expense will be if they attempt to modify the aircraft to operate from the carriers and the carriers to handle non-Russian aircraft.
If we go by your argument, it's better to buy the Rafale-M because IAF will soon be the operator of Rafales through the GTG.
Commonality simply won't work? Just because they need to work in different theatres of operations, does that mean they need different types of maintenance facilities? weapons depots? armaments? spares? differently trained technicians? what?
The infrastructure is all the same wherever you go.
Our geography is so vast that Rafale bases in Sirsa and Hasimara will not affect IN's base in Vizag or Nicobar. You ultimately have to train the same number of people, get the same amount of bases, get the same amount of spares etc.
MiG-29K is enough for a threat from the Arabian Sea but not from SCS. Also, US is buying additional Shornets because the F-35C is late and the older Hornets are retiring. And not because of the reason you pointed out.
USN's SH purchase has nothing to do with the F-35 being late. They plan to replace their older Hornets with the F-35 and they plan to replace their SHs with the new F/A-XX.
And how does operating the same aircraft by two forces make a country weaker?? What kind of an illogical argument is that?
UK - RAF and RN both operated Harriers
France - AdlA and Navy both operate Rafales
Russia - Su-27/Su-33
China - J-11/J-15
US operates different jets because it can and also their requirements were different.
Most of those examples are small countries. UK and France are very small as countries, their orders are also small.
The Soviets planned to build different aircraft for carrier aviation, which got junked. The F-35B uses the same propulsion design as the Soviet Yak-141, which LM bought after the Soviet dissolution. Even they had plans of building new carriers with dedicated aircraft.
US, India and China will have large carrier forces eventually. So the navies can justify having their own independent programs. Our navy will eventually have an air force that is more numerous and powerful than the PAF, think about it.
The US operates different aircraft because the planners know how important it is for the navy to be independent.
That's also why, if we setup theater commands, the navy will get their own independent command in the south. Which means the navy will be in charge of the army and air force in the Southern Command. The army and air force do not have a clue about how the navy operates, but the navy has a pretty good idea about how the army and air force operate. Do you see why it's important to let the navy do their own thing?