Yes, that's a fair point, many agencies are simply taking a "finders fee" there now and washing their hands of anything that happens after, they have nothing to do with looking after the pilot if there is a problem. Apart from that, anyone who goes through an agency and is told "when we get paid, we will pay you" needs his head examined. The primary reason pilots deal through agencies when they're flying somewhere they don't know much about is to ensure they get paid!
Caveat emptor - ask the questions, you have no excuses as there are plenty expats down there to tell you who pays on time, who actually has a roster, who provides decent accomodation, who maintains their aircraft, and who is "sneaky". And, I'm sure, a few who will snigger at the claim that an agency can have you in India and flying with the airline within 30 days!!