The RAF needs to invest more in realistic full mission simulators and make better use of them. There is no reason why they could not replace some flying hours; however, both the aircrew and the aircraft need to be exercised regularly to achieve success. Aircraft that last flew last month are probably not going to work much better than aircrew who have not flown for a month.
The sooner simulators are linked together for full mission training the better. Then one will be able to practise war scenarios operating with real players and simulated 'real' weapons.