but if japan captures it, they're pumping out 3 tanks per turn to wreak havoc in russia/middle east/asia/africa
Doesn't bother me. If the UK dropped an IC on south africa as I mentioned above, they're already countering with two tanks per turn. If I have my way, the US has already taken the few IPC loss of taking venezuala, is parking transports off Brazil and running tanks from the western US down to Brazil and across to Africa by the time Japan takes India. Japan is going to save dropping the extra transports, but chances are they're coming anyway. They'll need a lot more than three tanks to stop me so those tanks will be busy unless Germany manages to get in my way, which takes pressure off the other end of Russia and taking pressure off Russia is all that matters.
If the IC in India baits Japan away from Russia, that's good. They can fight whatever Britain drops and if they capture it before the forces link up from Africa, it just means I get to bomb Japan with SBRs for rental.