I have an extremely simple cure for this entire problem. It could be implemented in a matter of months, and it is guaranteed to produce a security workforce that is competent, fast, helpful, friendly and efficent
Offer to pay the Security Guards 200,000 pounds a year.
It's always the same problem when you hear the "we can't recruit enough staff" what they really mean is "We can't find competent people who will work for us for the miserable amount we are offering to pay them
To put it another way you get what you pay for