It's a no-brainer. The papers can't simply be same, or the paper would definitely get leaked...
Say, a group of students decide to send someone, who is only giving a mock this year (i.e. has to take a drop definitely) in the first slot and then leech off the paper, and get say 30-40 marks more that they would otherwise had not been able to score. In return, they pay the first kid.
And, for the difficulty, I cannot say anything. Cut-off dropped significantly last year, which means that either the crowd's intellectual capacity dropped, or the paper had been of good difficulty. In either case, I don't think that the paper setting board would be bothered much by Kalpit's or any other person's comment. They have to go with the masses.
And, say, even if the paper is tougher than last year, then it wouldn't make any difference, because the drop in cut-off would account for that. Paper being easy or difficult doesn't mater (unless there are extremes ofcourse), rank does.