I see what you are saying but I have to disagree.
Playing in D2 even against bots as you claim and bad managers still pull in more revenue than D4. Now for examples sake, I was pulling in 250k net a week easily when I got promoted into D2. Assuming a conservative side accounting for more bot teams, lets say 200k a week. (although technically the difference should not matter as much as income takings is more aligned to your position on the table and the opponent you are playing rather than the fact a team is bot)
This is still significantly more than D4. In D4, a good manager will be able to pull in 70k net a week or so. You just can't compare the divisions. Negating the effects of training, and day trading, etc, over the course of a 14 week season a D2 team would be able to pull in 200,000 x 14 = 2.8 mill while a D4 team would pull in 70,000 X 14 = 980k.
As a D2 team, you are still almost 2 mill better off and looking at your roster and how low your salaries are, I would guess that you can easily pull over 200k a week. In fact from your arena, just your last home game you made 200k. Good luck trying to make that in a home game in D4.
The chunk of change you get for promotion is minimal. Thats like an extra week of income. Hardly makes up for the 2 mill difference in income you get over a course of a season.
I don't think there is a point trying to compare manager skill levels. We all play the game differently and have had different paths in reaching their current state. But you are right. Lets get off this discussion and go back to the original topic :)