Boomer
While there may be differences due to manager lvl, this game doesn't have too drastic a performance difference between manager levels (especially once your tech levels are 15 and above). Also, since car design is reset at the beginning, everyone basically starts on even ground save for manager levels. Managers who are more knowledgeable about the game and happen to be more skilled relative to their competition will easily overcome manager level deficits, so it's not unusual that someone can challenge for victory in Elite even in their first season once they've caught up with car design.
Even in the game's best leagues, managers have come into Elite and managed to win races in their first or second season. Some managers can do this even with relatively low level manager level (think lvl 15, 16). Nothing unusual with seeing them challenging for the championship too.
I just haven't met these guys I think ;-), but some are really close.