ok sisyphos, jtr has had a go, now its my turn.
Lets imagine that there are no new aircraft ordered. Command rate would depend on retirement rate so lets assume about 60 per year. So that would mean no commands for the next 5 years until this guys get to 60yo.
Now lets assume an expansion that requires say 70captains for new aircraft adn 60captains for retirement. Over the next 5 years we will need 650 captains...or with RA60 about 350captains.
So yes sisyphos you are correct....- expansion will dampen the effect of upgrade delays significantly. If you were FO no 351on the seniority list your command would be nearly 3 years from now or not at all with RA60. Now this FO #351 will earn command pay for two years less and always be 2 increments less for his entire career. So if you look at his career earnings at age 55, he will have significantly less career earnings than with RA55. He will probably earn that much money by about 57-59...I will work it out accurately some other time.
So not only does RA60 mean a later command/later upgrade to C+T etc, it also means less money in your career until somewhere between 56 and 60 where you finally catch up with what you should have had at 55.
Guys, beware of the sophistic logic being applied by the protagonists for RA60!