The numbers issue with respect to plus or minus a soccer player is important...
However, you have struck an issue that will have even greater ramifications over the long run, and that is, when should travel play begin?
It is an integral part of the developmental issue, because, currently youth soccer players in the crucial U9 to U12 age groups are being "selected out" for "elite" or travel teams.
Most often the basis for this "selection" is physical maturity. This is a tremendous detriment to ultimately producing better and greater numbers of youth soccer players because it is at these ages that the early or late onset of puberty creates a huge and, in many cases, false picture of who ultimately will develop into the best youth soccer players.
Because of our "travel" leagues at these ages we are selecting a few out for "better competition" and "better instruction" and opportunity. This early selection process is retarding our development as a soccer nation from all angles.
First, the "player" (I have yet to see a real "player" under 15 or 16 (Freddie Adu is a rare exception) who is selected is forced to rely on his "strengths" to succeed, with little opportunity to develop in areas that he has weaknesses. If his or her strength is physical (which it most often is at this age), then when others catch up, this youth soccer player usually becomes very ordinary.
Second, by creating "travel" teams at these ages we are placing a premium on record (regardless of score keeping), and to succeed players most often become role players, rather than being allowed, or encouraged, to develop into more well-rounded and diverse players.
A third problem is represented by the youth soccer players we leave out. While some persevere and develop into travel players later, many drop out of the sport. We live in a society where instant gratification and obtaining the edge as early as possible are the norm.
I don't know about western New York or Cleveland, but in the Northern Virginia area, we literally have people signing their kids up for certain pre-schools before they are even born, just to make sure they can get into the "right" kindergartens later. The perception is that if we don't do more, earlier, we will be left behind.
Therefore, our kids are placed under tremendous pressure to be the best as early as possible. This is fed by leagues that want to make more and more money with multiple divisions, and tournaments. After all, when a league or club has a travel tournament, it means, by definition, that many teams will have to come from out of town. Well, how many parents accompany their 16 or 17 year old kids to tournaments compared to parents of 9 year olds?
Therefore, it is the 9 year old, etc, brackets that produce most of the hotel and restaurant revenue. Similarly, who buys all the candy and t-shirts?
It also spawns incredible amounts of recruiting, which is, in many cases, promoted by having "professional" coaches at early ages. While most of these coaches have played the game, many have no clue about the myriad aspects of child development. They know the game, but they don't know the "player." Most often, they try to fit kids into a mode of training that is reminiscent of their most recent playing days in college or high school.
Hence, they play upon parents' fears of success for their child by spouting the need for commitment and playing more games and tournaments, etc. and the fact that they have the "secret" to success. Obviously, the issue of coaching education is tremendously important, but only a part of the issue.
It takes a long time for a soccer player to develop, and one of the driving factors to long-term development is a passion or love for the game. Right now, we force our kids to compete before they ever learn to play or enjoy playing. If there is any doubt about this, try to find a pick-up game among kids in a park. They are almost non-existent, because soccer is a sport that they play when their parents take them to a certain field, with certain players who make up their team, and under the guise of a certain coach.
We have it all backwards.
The key issue that will hound us for the next ten years. In a sense, if all players of these ages (U8 through U12) had to play locally in "transitional" leagues (whether within one club if it were big enough, or within a 2 or three club league), then the issues of numbers of players a side, etc. would be solved quickly.
For instance, if between two contiguous clubs had between them 100 players in a particular age group, they would much more readily accept playing 6 v 6 ( hypothetically with team rosters at 10), than if they were only looking to find two teams of 16 to play in a travel league made up of players from many different clubs.
Anyway, I am glad you mentioned the issue. Moving to smaller sides is tremendously important, but is only one part of a bigger issue. I guess we can only eat an elephant one bite at a time.