That really depends on the organization but yeah promotions beyond a certain level depend on a lot of things including how much said person is concerned with rank. Personally speaking Serge, based on time, skill, knowledge, background and attitude, should be the ranking Aikidoka in your region - please give him and all my regards.
When I joined the dojo there was a 63 year old man who was there about 6 months previously. We both did our Dan grade togeather (I nearly killed him when he was my uke) and while I was in Quebec he did his nidan. He did all that was required and worked hard but physically he was no where near the 25 year olds. He has a habit of over-explaining things and when I grumbled about this to one of the seniors (just for grumbling sake) the comment was that he had an old man dan grade and doesn't reallize it. So is this honorary or adapted to circumstance. The story is positive because annoying habit aside the man is an inspiration and he can do the full splits.
Originally posted by Carl Simard
Simply want to add to any dan above the 4th are more or less honorary and doesn't necessarely reflect the skills... For example, a difference between a 4th and 5th may simply be that the 5th open a dojo in a region where there was none and, so, contribute to spread aikido (and bring new members to the associated federation)... That doesn't meand that the 5th is certainly a better aikidoka from a techical skills... He may then get his 6th because he write some books on aikido... And so on...