Others that were considered
In addition to the five stars who had there own slides, there were some other wrestlers who might have fit in for one reason or another. Someone like Damian Priest has time on the independent scene that could be utilized in the group. He's also like a more slender Roman Reigns but with a darker edge. I'm not sure how far the "Live Forever" and archer gimmick will go, but the man playing the role is talented enough to pull anything off. He's high-flying, intense and could be a big star in the future.
Other big guys like Babatunde or Dominik Dijakovic would have worked due to their sheer size. Wrestlers like that give any conquering faction credibility and if they were a part of a group, then they wouldn't need to speak. Dijakovic is okay on the mic, but his in-ring work is clearly his strength.
A top AEW star just called one of his colleagues 'spoiled' and 'narcissistic' HERE.
If I was to pick three new members to form a new Shield, I would pick Shane Thorne, Isaiah Scott and Daniel Vidot. Thorne and Scott are known enough due to work in NXT and on the independent scene. Thorne needs something to put him over the top while Vidot could be the wildcard of the group.
WWE could go with a strictly Aussie lineup by switching out Scott with Reed. Whatever the case would be, it wouldn't surprise me if they tried to form a new group of current NXT stars that somewhat resembled the Shield. While it might not be as good as the original, it doesn't mean that the WWE won't try something from the past to help get an uptick in the ratings.