Guys, only Zabuza was involved in the coup. This has nothing to do with the other members of the 7 swordsmen.

Keep in mind, the whole reason Zabuza was working for that one mob guy was to raise enough money to attempt another assassination. Why wouldn't the other swordsmen help him with this if their goals were the same?

Also, just because Zabuza and Kisame are missing nins that happened to be among the 7, doesn't mean that the remaining 5 were as well.