After 3 years at BA I have 2 stripes, till year 4. My mate who joined Flybe at the same time I joined BA has just got his command (4 bars).
Its all down to the company, not always a sign of knowledge/competence/ability. Even the 'newbies' to BA who may have thousands of hours ex RAF or another carrier will have 2 bars for four years.
ATB.