You don't have to have 1500 hours as in FAA land, or thousands of hours in GA land as Australia, or have been a Fast Jet ace, to be a competent and safe airline co pilot. For many years in Europe, (EasyJet/BA for example) 250 plus hour "Cadet Pilots" have gone straight into the RHS of B737/Airbus A320 family, on two pilot operations.
It's the selection and training that matter, not thousands of hours instructing in a C172 for example.
In my UK airline, after rigorous selection and after 200 hours or so in a flight trying school, attaining ATPL exams and an MEP I/R they started their airline careers.
Firstly a normal Type Rating technical and and Sim Course. Then Base Training on type covering all emergency ops required for two pilot crewing. (We don't employ partially trained S/O/Cruise pilots)
Then up to 50 line training sector's with training and supervisory Capts. When released to normal line operations they are then not rostered with new Capts. for the first 6 months. These "cadet pilots" have since carried out long safe careers, the first examples retiring as Concord and B747 Capts. for example.
Its the training not the hours that count.