The only way to a quick command is to either join an airline with a high turnover or one that is expanding. High turnover = poor conditions. Good conditions = low turnover. There is also the danger of joining a new airline that is expanding just until you join. With relatively young crew, it will take some time to get a steady stream of retirements and the new joiner will spend even more time in the right seat.
Simple mathematics would say that in an airline that is neither expanding nor contracting will have crew spend the same ratio of average career time in each position as the ratio of pilots in those positions. For example, if the average age of joining is 30 and average time of retirement 60, there is a career of 30 years. If the crew numbers are 1/3 Second Officer, 1/3 First Officer, 1/3 Captain, then you can expect to spend 1/3 of your time in each position. That is, 10 years in each rank. If the airline is expanding, quick promotion. Airline shrinking, slower promotion.
Now, if you join an airline that expands rapidly for 5 years and the average age of the crew is young so no retirements, and they stop expanding, you could be an F/O (or S/O) for a VERY long time.
These low-cost/pay airlines are kind of like a pyramid selling scheme for crew. Get in quick, get a quick command, and you are sweet, as the captain pay may be well less than the 'legacy' airlines, but you are on that captain pay for way, way longer. Last one in and you are pretty much screwed.