Submissions moves from throws and strikes.

[lawdog]

I like to transition to a shoulder choke (kata gatame) from o soto gari

Yes, that's much more effective than a juji from O-soto.

Realistically, most O-sotogaris will end up with you going down with your opponent and landing more or less on top of him. The kata gatame transition requires much less movement and flows much more smoothly from o-soto.

[Te No Kage!]

for those that are Japanese challenged:

O soto gari


Kata gatame

[daigoro]

In Enshin Competitions takedowns are allowed but it pretty much ends there. There isn't any groundfighting in the competitions. So I don't really know how these got worked into the curriculum, unless there was some pollination from Shidokan.

This is just a SD technique. If you look at Niniomiya's books/videos you'll see arm bars and triangle chokes.