As to whether the events of Matthew 27 could have happened, the answer is “of course.” It was a miracle, worked by God. The fact that we know very little about these people, how or why this happened, or what happened to them, does not make the miracle any less real.
We can’t prove this miracle, but we do have trustworthy testimony from people who witnessed it. There are no accounts from that time period of people refuting what the Gospels claim and the Bible has been proven to be historically accurate in its records of historical events.
So, the question for non-believers should not be if a miracle recorded in the Bible is true. Instead, it should be whether or not the Miracle Worker is real. Non-believers understand that if God exists, then miracles are not only possible, they are to be expected. Non-believers reject the Miracle Worker, who is God. And as long as they desire to reject God, they will cast doubt on His miracles, including the one in Matthew 27. For fun, take a quiz on Five Miracles in the Bible