The Indian Cricket Board is totally different from other countries and we also know that Indian cricket board is the most powerful and richest cricket board in the world. They spend more money on developing each player and also keep alternatives for them so that the country does not have to face any kind of problem in cricket. The country's cricket board gives cricket the highest priority and takes every step. They list reserve players according to categories. Especially in big events, all that is reflected. It is said that India is producer for producing good cricketers. They have alternatives for every player in the national team. I have no reason to think that the players in the India 'A' team are any less qualified than the players in the national team.
That is really amazing how Indian Cricket Board stands out. And yes their wealth as key allowing them to spend much on developing players and always having strong backups for national team. I am also impressed by how well they plan especially in big games where their deep pool of talented cricketers shines. Essentially India consistently creates great players and even A team members are just as good as those on main squad.