Sure, why not. It's probably not the most realistic, but I think this team would at least be good to very good. In my eyes Seiya is gone. Someone is going to give him 5 years at 20-25 a year and that's just too much even if this OF class sucks. Also, I don't really want Happ back, but I think I'd throw a QO at him because this OF class sucks and you could do a lot worse than him on a one year deal.
Bringing Holmes back is almost a no brainer in my eyes and I'd throw him something like 3/80, though a 4th year might be required.
I'd also love to bring Peterson too as they seemed to figure something out with him. He had 1 absolute disaster start in the 10ER performance and 1 more bad start with a 6 ER peformance. Besides those two, he never gave up more than 3 ER in any appearance. Is 2/24 enough?
I'm just assuming Horton wont see any time in 2027 and I would rather never see Shaw in a Cub uniform again so I'd like to see a big SP acquisition
Shaw+Kepley+Wing for Reid Detmers
Adrian Morejon is a dominant lefty who is nails on everyone lefty or not and is the big splash the pen desperately needs, but he going to be expensive. 4/80.
I'd like to bring in Brooks Raley as your lefty on lefty guy. 2/8 to 2/10 would do it.
I'm not sure he'd be open to it and honestly the Cubs might be better off just splurging to keep Seiya instead, because at least Seiya can play RF adequately, but the last piece I'd like to add is Randy Arozarena. I don't think he takes the 5 years it's going to take for Seiya, but the AAV is probably not all that far off. He's basically a pretty reliable mid 120s wRC+ bat so I think the ask would be around 4/88 while I think Seiya ends up going around 5/120.
C- Ayers/Amaya
1B- Busch
2B- Nico
SS- Dansby
3B- Bregman
LF- Happ
CF- PCA
RF- Pedro
DH- Arozarena
SP: Steele/Detmers/Brown/Holmes/Peterson/Garrett/Assad
RP: Morejon/Palencia/Zeferjahns/Miller/Webb/Raley
It's probably a little overzealous given that the payroll would be increased even before addressing the bench and arbitration, but it is a team I think would give them a legit shot.