We don’t know if any of them are who they claim to be. You can look at what Trump has accomplished and see that he gets things done. There are some governors in the race who have accomplishments, but you never know what will happen once they get in the WH either - so it’s a crap shoot. Look at some past governors and their legacies in the WH - they weren’t what they claimed to be either.
Cruz has been “on message” his entire (admittedly short) career. That makes me fairly confident that Cruz is “as advertised.”
Trump has swapped sides at least once (twice if I am not mistaken!). That is what creates doubts about Trump for me.