The Shield is weird now because the league doesn't have any sort of balanced schedule so it doesn't mean anything particularly standardized.
My pipe dream is to manufacture a balanced schedule. For the sake of making the math easy, imagine a 36-team league. Split into three 12-team division and play everyone in the division twice = 22 games.
Then, the top 4 teams in each division advance to another group. Teams 5-8 go to their own group and teams 9-12 to their own. Points against teams that advance to the same groups roll over.
Each team then plays the eight teams they haven't yet played twice = 16 more games for a total of 38. So all the shield contenders will have played the same opponents. The winner of the top group gets the shield.
And for the playoffs, you can take the top 4 finishers in the top group, the top 2 finishers in the bottom group, and the winner of the bottom group. Give the shield winner a bye. (Or whatever. But take some teams from all groups but more from the higher groups.)
So the shield is "fair", everyone is playing meaningful matches into the final third of the season, and the early matches have a pretty significant sense of urgency.