Well I can only think they didn't cast Mark Hamill or his contemporaries because he was too old for the timeline of the story they were trying to tell. Maybe some of the other cast members pay grades had risen beyond what the studio would cover (the movie already had some other budget issues iirc? Or were busy with other projects? But ya absolutely love the cast in Wing Commander 4-5. Ya the cloaked fighters subplot that thing starts really early in Super Wing Commander from the first or second mission of the main story. It's one of the first things Shotglass mentions rumors about, and then Maniac and Hunter talking about it too. Then during the briefing Halycion mentions it and tells people not to talk about it since it's classified and anyone caught talking about will me military disciplined. There is a whole side story about that that builds up throughout Super Wing Commander along with additional "new cutscenes" related to it as well. 1.5's additions to that probably seem really out of place without understanding about the "extended" content relating around that subplot. But otherwise 99% of the dialogue from 1.5 is just stripped down version of SM2 diaologue (stripped only of the Firekkan references). The issues with the cloaking device also occurs in Roberts Wing Commander Academy series too. That series used Mark Hamil, Thomas Wilson, and Malcom McDowell from the tv show as well.