In my dojo we have so few students that we run some of the techniques of different levels together. This allows our 7th kyu to at least get a feeling for Saifa kata along with his required Gekisai dai san. When testing comes he may perform both kata but really will only be evaluated on the Gekisai Dai san.
This overlap is good in that he gets exposed to Saifa and when I start working on Gekki Ha he can peal off and work on his Gekisai dai san.
Having only four kyus in our club has its challenges, but by working on same techniques we can get better together. It's easier because there isn't much separation between us. We have one 7th kyu,two 6th kyus and myself, a 5th kyu. I can see that it could be more difficult if the ranks were more spread apart. By being a small club and close in rank it's easier to motivate each other.