Captain stable
Maybe years ago when you could buy anything in the USA and half the examiners instructors with it, but things are very different nowadays and have been tightened up considerably.
Examine the training requirements and tolerance requirements of both IRs compared to the IMCR and they are no where near the same. What makes the EASA IR harder in flight training requirements than the FAA IR done by the book?
Again off topic examine the major study carried out between the two systems and the resultant ATPs are equal in the safety stats.
Pace