I don't doubt that some, if not all, of this is true. But what they do have on other "have" teams in the OHL like Kitchener, Windsor, etc, is that they have the best building in the OHL. Since that building brings in huge $$$, the team has the financial resources to have the best scouts and enough of these scouts to see many more games than most other teams so that when they take a player in the 8th or 9th round, chances are they've seen that player enough times to be sure that said player has a better chance to become an asset going forward.
They have a staff/ownership of ex-NHLers who have huge connections with NHL teams which is big when such teams own the rights to players they've drafted and hope to recruit. These ex-NHLers also have huge connections with agents and probably better rapport than other OHL teams. This is big because it is the agents who direct their import prospects to report to the teams that will best chance at development. The import draft is pretty much cooked. Many of the players know where they're going before they're picked. An agent will put it out there that a certain player will only go to a certain team. The rest is history.
Another thing London has on most other OHL teams: They own the team and aren't going anywhere. Aside from high end education, one of the biggest attractions that NCAA schools have in recruiting players is that they can sell the players on the fact that Jeff Jackson, Red Berenson, etc etc, will be your coach for your entire time as an NCAA hockey player. Most of the high end NCAA schools have stability in their coaches. You can commit to a school knowing that you won't have to wonder who your coach will be from one year to the next. Dale Hunter will be coaching London on an indefinite basis. Basil isn't going anywhere. Neither is Mark despite his job with the Leafs. The man can walk and chew gum at the same time.
A team like Kitchener on the other hand, despite being a "have" team, has had a continuous coaching carousel outside of the DeBoer (7 years) and Spott (5 years) stints since the early 90's. Quick example: a player like Kitchener's Darby Llewellyn. If he is utilized as an OA for the upcoming year, he will be coached by his fourth different coach in 5 years in Kitchener. As much a "have" team as Kitchener is, they can't recruit players and guarantee them that they'll be coached by the same coach for their entire time with the team, but London can, and it matters!