The Trump campaign's attempts to lower expectations are so blatant.
The thing is though, even if these stories about his debate prep are true (they're not), it's yet another reason to vote against him. Can't even be bothered to research his opponent, apparently. He's really going to make Pence do all the work if he's elected, isn't he?
It's clear he has a strategy. Everyone is expecting the debate to be a trainwreck for him, so he'll come on stage calm and subdued ("presidential") and immediately impress. He'll try to get away with not knowing anything by tearing down Clinton as opposed to talking himself up. It's her job to make sure viewers see through it.