One guy in my league never got anything above 103, while you managed to get 104—so you were luckier than some.
At the end of the day, it all comes down to luck. Some get lucky, some don’t. If you check the pack probabilities, you’ll see that the odds are stacked against you, and most days, you're expected to pull 101 or 102-rated players. This has been discussed countless times across different platforms (here, Discord, etc.), throughout different events and seasons and it's unlikely to change.
Regarding Manager Mode, EA staff probably provide more insights around the details. But keep in mind that it's an autoplayed mode with minimal input, your team either wins or loses, but your influence on the outcome is limited. You can read guides on optimizing your team and ranking them up within your resources, which might help. Personally, I don’t see much point in playing MM since you don’t have real control over the results and you just watch the screen waiting for the game to finish.
As for other Division Rival modes:
*H2H* is the closest to a skill-based mode, where OVR and training help but aren’t the deciding factors.
*VSA* is mostly an OVR race—higher OVR (plus training) gives you better chances. Most of the time, you’ll face opponents with a similar OVR and skill level.
That said, some players (like me) don’t actively play DR, so if you run into my 110-rated lineup that could be highly ranked if i played religuiously, it’s probably just because I need to complete an objective from a daily task rather than seriously competing—especially given the average awards and number of cheaters in DR mode (mind you there are less of them now than in the past). There are thousands of people like me so you will see them in your prescribed divisions,