3800 possible prosecution witnesses in the James Holmes mass-murder trial

Prosecutors in the Aurora CO theater mass murder have listed 3800 people as possible witnesses in the trial of James Holmes.  Looks like the prosecutors are into gaming the defense.  They couldn't possibly need that many.  It appears that the only real issue will be the insanity defense.  Holmes has asked for a change of venue.  I think that motion should be granted given the pretrial publicity and other factors