From the TRO 3067 entry for the Tatsu:
Once the Combine had mastered the technology of OmniMechs - the first one walked off the assembly lines in May of 3052 - its next logical next step was to tackle the OmniFighter. This proved much more difficult, however, and years would pass before a prototype OmniFighter would fly the skies. Finally, though plagued with problems, the Coordinator authorized the production and release of the Sai OmniFighter - a direct conversion of the craft whose production plant had been overrun by the Smoke Jaguars.
This makes the most sense if it's referring to the S-4 Sai, since the Tatsu (3063) is supposed to be released after the Sai and the S-7 Sai is a 3065 design. So is the S-4 Sai an Omnifighter??
