First have you even tried to play back any of these clips, I have a FS-100 and FCP (or QT Player) will not playback material recorded in Raw DV, but that maybe because the camera is outputting DVCPro50 or HD.
But if the clips play fine there is a semi=painless way of merging the clips. If you have not started and stopped throughout the game…
Do this for a single camera at a time. Bring all the clips into the BIn of FCP (sort by name). Select all the clip and drag to the timeline (make sure your seq. settings match your clip). If you don’t care about preserving the TC on the clips Export this seq “With QuickTime” make the movie self-contained. Work with these new clips.
If you need to preserve the clips TC or if there are gaps in the recording (Stopping and starting throughout a single game). Drag the first clips to the timeline and adjust the seq’s TC to start on the same TC as the first clip. Then bring down all the other clips, if there is a gap just move the next starting clip to matching TC in the seq, this will leave a gap where the camera was stopped but all the clips should line up when they are all done.
There is no way around these small clips on a Firestore, drives are formatted as FAT32 which have a 2 GB limit. Your problem only comes into play when you are trying to do a mutlicam edit like yourself.