Maybe so - but some do it much better than others.
A lot of trainers can be like 20-year-old skanks with a loser boyfriend .. 'Just wait and see how good he is when I change him'
The alchemist trainers are the ones who routinely do change them in a big way.. the trainers who are mere mortals might hit a double or home run once every blue moon .. but they also whiff a whole lot.
Here's a video of Deadly Dealer's stakes win from a few weeks ago courtesy of the DRF Stakes Results board... he ran like he was utterly possessed.
http://www1.drf.com/displayVideo.do?...=D&country=USA