Spending a career as an FO on the 744 and A380 an SQ FO would be lucky to average one pilot flying sector a month over 12 years.
To expect any person to be able to handle an aircraft to certified limits, with degraded systems, and poor conditions with this level of inexperience is a recipe for disaster.
Despite logging thousands of hours in the cruise, they would be lucky to have hand flown the aircraft for 3 hours over a dozen years.