I'm still sticking with my preferred choice, which is Aston Villa.
It would be very difficult for Aston Villa to replicate their form of last season, they now play in the Champions League, thus more games, a game every 3 days means a tighter schedule, more fatigue and it is difficult for smaller teams to cope with it. In the 2022/2023 season, Newcastle were the dark horse, look what happened to them in 23/24 season when they played in the CL, i fear that's what's going to happen to Aston Villa this season. I might also add that they lost Douglas Luiz, who moved to Juventus, he was a very important player for them last season.
Your analysis I think is very correct is is very similar to what I'll add now. Aston Villa despite their historic achievements of last season is still an average team and can't be measured with the likes of Manchester City, Arsenal, Liverpool, Chelsea and even Manchester United when it comes to possession of quality players. Unai Emery's men managed to deliver an incredible campaign last that saw them finish in the top four of the English Premier League table this season but i think they were able to achieve that because they weren't playing in the UEFA Champions League unlike this season that they'll participate in the competition. Aston Villa might do well this season by finish in the top half of the league table but I doubt they'll near the top four this season.