Caution and careful testing is needed. i had about 399 fighters attack a shivan demon at the same time, the result was that collision was out of working order, as I could fly inside as well as in and out of the demon. Pretty cool, except that frame rates was less than 2

. Only guessing. Did not have my -showfps command line option then.
To low frame rates seem to be messing with collision code.
Once I ordered the 398 ships to warp, collision worked fine again.
Too many asteroids combined with to many ships can have the same effect and lower system specifications will increase the possibility of this happening.