Re: X-MEN: FIRST CLASS - Grading+Discussion **SPOILERS!**
Singer and Vaughn most likely ignored elements of X3 that they didn't like or that were changed from the script the two of them originally were attached to...basically they ignored all the Ratner/Penn stuff. IIRC the casting of Kelsey Grammer as Beast was under Vaughn's watch.
Chief of Operations
Ignoring the The Last Stand since 2011.