Don't agree and neither do I agree with anything so far mentioned in this thread.

The first thing a fast bowler needs is PACE. You can't coach pace, it's either there or it isn't, whereas you CAN coach a repeatable action, line and length and pretty much everything else but you still cannot coach pace.

It's no different to genuine swing bowlers, either they have an action that naturally swings the ball or they do not and no amount of coaching will turn a non-swing bowler into a swing bowler. You can of course coach how to control swing and harness it but you cannot coach someone to swing the ball if their natural action does not do it.

So what use is a naturally repeatable action if the ball bowled is totally inefective? Without pace, seam, bounce, control or swing a repeatable action is worthless.