As far as I know, world rankings are calculated based on points from the last two seasons. So if a team doesn’t have continuity, it can easily move up and down.
Lebanon, specifically, has had a fairly solid roster in recent seasons, which is the result of their former French head coach who obviously built a system and found enough interested managers willing to train Lebanese national team players. I believe that in the past there were many more managers involved.
Israel, for example, is a BB powerhouse with fewer than 200 managers because they have a perfect system in place.
During my 10 seasons with the Serbian national team, we trained exceptionally well. The result was a silver medal in Season 11, when a new head coach took over, but the system was already established and the players had been properly developed from start to finish. That’s why Serbia is now rising again in the rankings, and I hope we will stay there for a longer period.
With good organization, a strong system, and perfect cooperation with managers, results are only a matter of time. For the U21 team, results don’t require a long period of time, but they do require a lot of dedication. For the senior (A) team, time is necessary if the current roster is not competitive enough.