No, I don't think it's true. Being connected to other people doesn't make you bigger, or stronger. You are as big or strong as you are. However, having a network of people whose resources are at your disposal certainly HELPS. The Church's point, and Hubbard's, is that there are some people that damage you through being connected to them. I think that this is true. The easiest example is addictive drug-users. Most people who have experience of dealing with these people will know that unless they are really exceptional people, they often cheat, lie or steal, have unexpected lapses in performance, and are otherwise unreliable. I have known some people who were addicts that managed to limit the damage of their drug use to their private lives, but this is the exception. Typically, association with these people has serious costs for people who know them in terms of turbulence, loss of assets, wasting time trying to deal with someone else's problem, shame, humiliation, etc. There are other sorts of people who are also negative to be associated with (people who constantly cut you down, continuously cannot be trusted to handle the challenges that confront them, etc.). In each case, you have to decide whether the price of association with that person is worth whatever you gain by association with them, or in rare cases, where you simply decide to take the losses for the other person's sake while you try to help them survive.
Disconnection is sometimes warranted. Handling is sometimes needed. My problem isn't with the CONCEPT of disconnection or handling, so much as the way in which this concept is used as a weapon or a tool of manipulation by the Church.