For Indian MiC to do what you suggest would need a) legalization of lobbying b) sure shot chances of winning contracts. Its easy for outsiders to do because Indian Market is like a gamble if you win you win big if you loose and get caught you shall be debarred as Indian law can at max do that to a offshore company on whom Indian rules dont apply.Paisa matters, if they pay 100K, Indian MiC should be willing to pay 200K, or even 500K. For someone who is willing to sell their country for 100K, they would definitely sell their soul for 500K. Again as i say, Private MiC doesn't know how to manipulate politicians. They could recover the costs from even the aftersales support money. Afterall how much can a money can be utilized to lobby for 1 Billion$ deal? Atmost 10M$ or 50M$. They could very well recover in follow up orders or aftersales support or such. Atmost they have to eat less profit but any profit is better than 0 revenue.
OTOH local defence deals getting bad name has far greater recurssions for local companies. Laws are pretty strict. So what you suggest is impractical and hysterical to say the least.