Dark Order and Jimmy could be good but I think Dark Order would have to ditch the minions and maybe even that tag team name.
PAC would be a great fit and give the stable some real legitimacy and make them threatening but I think he's too over on his own right now. It would take away from that and I think he might overshadow the rest of the group.
I kind of like the idea of Janela, Jimmy and someone else. I like both of them but I can't see AEW doing a whole lot with either of those two anytime soon. Would Kip Sabian fit there too? I know very little about him.
If Spears can't get over at all for some reason and they don't push him, I think he would make an interesting addition. That group lacks a physically imposing type and he kind of fits the bill. I definitely prefer Spears to do his own thing though. Also, if they do the whole Marty is pissed at the elite and is getting revenge angle, that would make Spears fit even more after his run in with Cody.
If Dark Order don't get over in their current form, it could be an opportunity to repackage them and boost them up by affiliation, for sure.
I agree Pac's inclusion could cause some issues as he certainly has potential to overshadow Scurll. I think that could be useful in eventually playing up tensions between the two of them, though. Early on, I think it would make sense from Pac's perspective as his character has had a chip on his shoulder and feels he's being overlooked, so I could buy him partnering up with another prominent guy who feels he's been overlooked.
Sabian is definitely the type of guy I'm thinking about. He seems to have a lot of potential but is currently lacking direction and is pretty bland.
Spears makes sense as well, though he'd have to ditch Tully probably which I'm not sure is for the best. For that matter, Tully bringing another guy and/or girl under his wing wouldn't be a bad thing either. I think overall, they're doing a good job of putting the spot light on a lot of different people, but there's still a good chunk of the roster that could use a better direction, whether that's some sort of character, or angle, or faction that can boost them up.
EDIT: Wardlow is another guy that popped into my head. Putting him with a Villain group, or putting him with Blanchard, seems like it might be a good way for him to start. If they introduce him solo I can see him having some trouble getting over on his own.