I've had several ex-Bristol staff tell me that if their engineers had been given a look-in, the RB211 would never have been such a monumental f'up in its early days
How could they know that? The RB211 was revolutionary (no pun intended). They couldn't possibly have experience of it, no-one had made such an engine before. They may have had experience of developing new engines. So had the RR engineers. If it comes down to a pissing competition "we've got more experience than you of making new engines"-"oh no you haven't", then that's not very useful.