Hi DJ,
first off, these are not rhythms but
musical styles, each of which has its own history, rhythmical characteristics, typical instrumentations, etc etc... Charanga refers to an instrumentation/orchestra type primarily, for example. I suggest you try to find information material for each of these (and other) styles independently, without trying to relate or compare them to each other. Eventually you will understand the differences more thoroughly, and perhaps you will also understand why it is very hard to answer your question in a satisfactory way out of the blue.
http://www.timba.com is a great resource. Check Ben Lapidus for info on Changüí. Ned Sublette's "Cuba and It's Music" is always recommendable. The musical style originally associated with Charanga (Francesa) is Danzón. Famous Charangas are/have been: Orquesta de Antonio Romeu, Arcaño y sus Maravillas, Orquesta Aragón, Fajardo y su Charanga, Estrellas Cubanas and Ritmo Oriental (and many, many more). The man most commonly regarded as the creator of Son Montuno (although there might have been others) is Arsenio Rodríguez. He also was responsible for establishing the orchestration formate called Conjunto. There's a whole book out about Arsenio:
http://www.amazon.de/Arsenio-Rodriguez- ... 346&sr=1-1 .
You will also realize that Charangas play Sones and Guarachas, as well as Conjuntos playing Guarachas, Boleros, and even Cha-Cha-Chá.
So good luck! I (for one) will happily be at your service for more specific questions.
Thomas
P.S.: As to the videos; The conga tumbao called "Charanga" was named after the orchestra type. According to José Eladio Amat and Curtis Lanoue, "The charanga pattern comes from the style in which
charangas francesas played the son". However, there are enough Charanga tunes that do not use this type of tumbao. This is just one tumbao variation, same as the single-conga-pattern on one of your videos: Changuito associates that one with Son Montuno; it's just a way to play the tumbao! Your standard conga tumbao or ride pattern may be called tumbao or marcha, but also Son, Mambo, or Guaracha, because these are the styles to which the same tumbao is applied. -TA