Not sure if other training companies use them. I think Clyde used to be be associated with p&o for the Irish route but I'm not 100% sure. I only had one interview with Sstg and was told at the end id being successful. I was then given a list of companies who were taking cadets on at that time. I haven't had any interview or contact from P&O. I'm guessing they just allow Sstg to select candidates.