This topic led to a very interesting and long office conversation
and changed some people's opinions. The conclusion after seeing the video in this link that someone found:
Changing Tires: Tire Basics: Tire Care & Buying Guide: Michelin Tires
and even more discussion was - fit new tyres to the rear.
In normal driving you will begin to feel the front tyres losing grip (wet or dry) and can usually consider this as a warning and slow down, therefore avoiding an accident. If the rear tyres have less grip, they can go before the front with less warning, and a rear skid takes more skill to control. The less driving experience, the greater the risk.
In an emergency, it might be better to have more grip on the front tyres but if the car became unbalanced or was going around a bend/corner, once again, the rear tyres need to have more grip for reasons stated above. On a dry road, it was thought that the difference would be very small.
The subject of greater traction/grip for acceleration or starting on a muddy field was quickly dropped because this was 'convenience' not safety.
What will I do? I will continue fitting the best tyres to the rear and slow down in the wet if I begin to worry
!