The organic fighter idea may have some merit to it, as the "normal" Shivans are probably too large to fit into the fighters; as JFK said, one of the ST movies (shiphit2 I think, the one with the shivan banging on the thoth), although it is just supposed to be a joke, shows the relative scale of the shivans.
However, it would also introduce numerous problems; namely, how did the GTVA capture these things, and how did they fit Terran pilots into them? Obviously if the ship is an organism in itself, it has no inside space for anyone nor any standard controls, and if the ship can think and operate on its own, how did they get its "brain" to give up control of the ship to the player? The first issue can be rectified with some clever engineering, but I have no idea about the second one; they would need something like Yuri from RA2 to mind control the ship.

I think it is possible that the five-legged Shivans can actually fit into the smaller fighters, but unlike the Terran and Vasudan ships, they would be taking up most of the room inside instead of the usual reactor, weapons, etc. and the entire fighter would have to be shaped to accomodate them, which seems a rather inefficient use of space.
(But it is fun to speculate
)
which is the point of this thread.
