Mad Jock
I'm not so sure I agree with your comments about insurance requirements etc, but I do stand to be corrected and will go find the answers. I would however be surprised if what you say is correct as the issuance of an 'approved commercial licence' says it all. The holder has achieved the minimum JAA standard to operate an aicraft commercially, subject to the relevant type rating endorsement.
Subject to the above, my point is that certain airlines may set a criteria for consideration, which might be arbitary, hence my comments about 157 hours versus 1000 hours. At the end of the day, ability is what counts and my experience shows that the number of 'logged hours' is not the indicator for ability; far from it!
But, remember, that is their choice (the airlines, for example!)
Agree with MJ about practice. Instrument scan is paramount in an assessment, however you achieve it. That is more important than hours logged in a book; they are worthless, whilst ability is paramount!
Hope this helps.
Cb