This is why I'm always the guy at raids that splits the group. There's the higher individual ball bonus with the added incentive of splitting by team (Usually Mystic and Non-Mystic).
Kyogre with Blizzard costs lots of revives so in those cases larger groups may be better (since revives are an issue currently). If you are in a group with lots of revives you can still split it for damage balls but you are less likely to make it happen, especially since Kyogre is the hardest raid boss to date.
Another thing to keep in mind was the rainy weather in the second video. That probably contributed to taking more damage too.
I don't really see any problem with showing up in a large group with decent Lugias and high-level Snorlax. It's definitely an entirely different thing than using double-psychic Blisseys. The boss is going down either way and you have the people to back it up. The tradeoff is that no one is going to get many damage balls. It still influences the Team Bonus though so min-maxers need not fear that their efforts are for nothing (unless they're on Team Instinct)