Just to end the confusion on that numbers thing, the matches are 4v4, but you can have a team of 6. You don't need it unless you get to a match where it's best out of three (as far as I know, the only one is the VGC Championship match, but I didn't get far enough in past events to know). It's really so that you don't use the same 4v4 setup two or three rounds in a row against the same person.
However, it really doesn't matter in the rounds when its just one match since that's the only time you'll play the person.
Anyways. As for this setup:
kyogre / dialga / latias / kingdra / toxicroak / ludiclo
I'm still not the best at teambuilding, but it seems like this could fall to a quick RD team (which would have an easy job here since you are running a Rain Dance team, as well).
I was originally going to have Palkia on my team but switched in favor of Kindra and ended up having Mewtwo as my other Uber.
However, it really doesn't matter in the rounds when its just one match since that's the only time you'll play the person.
Anyways. As for this setup:
kyogre / dialga / latias / kingdra / toxicroak / ludiclo
I'm still not the best at teambuilding, but it seems like this could fall to a quick RD team (which would have an easy job here since you are running a Rain Dance team, as well).
I was originally going to have Palkia on my team but switched in favor of Kindra and ended up having Mewtwo as my other Uber.