A few things to mention here:
First of all it is too late to arrange extra drivers on the polict. Insurers will not back-dat changes.
When drivers are detected speeding by camera, the fixed penalty office (FPO) decides whether to go down the fixed penalty route or to issue a summons. 35mph will steer them down the FP route.
Irrespective of how the van�s owner (your friend�s employers), your friend and you decide how to play it (i.e. who you choose to say was driving) no check on that driver�s insurance status will be made.
In the very unlikely event that such checks are made, and it is determined that the driver was uninsured, he will be summonsed for both offences. (The system is such that if the speeding matter is complicated by any other offence, a fixed penalty is not offered).
If convicted of two (or more) motoring offences which were committed at the same time, magistrates apply fines for each offence, but award penalty points (or a disqualification if appropriate) only for the most serious.
So your friend would receive two fines, but only points or a disqualification for the No Insurance matter. As has been said this offence attracts a minimum of six and maximum of eight points. However, as with any offence which carries penalty points, magistrates can impose a disqualification for the offence instead of points.