Enforcing forfeits to get games played means you have no idea how the teams would've stacked up against each other and throws out the results.
Encouraging 4-player teams means you will have to eventually pick 3 of those 4 to put forward into future tourneys, etc, meaning that combination may not be the best combination or the one that was placed highly in the London league.
Having a play-off at the end of the league means you can decide on any kind of mini-tourney you like and the results should be more accurate between the top teams, fixtures are often not similar/comparable/fair when spread out over time (in comparison to a one day tourney at least).
Also, a shorter league means a more accurate representation of teams within that time frame... some teams may start out really bad and get really good by the end of a long league which throws out comparative results.
Enforcing forfeits to get games played means you have no idea how the teams would've stacked up against each other and throws out the results.
Encouraging 4-player teams means you will have to eventually pick 3 of those 4 to put forward into future tourneys, etc, meaning that combination may not be the best combination or the one that was placed highly in the London league.
Having a play-off at the end of the league means you can decide on any kind of mini-tourney you like and the results should be more accurate between the top teams, fixtures are often not similar/comparable/fair when spread out over time (in comparison to a one day tourney at least).
Also, a shorter league means a more accurate representation of teams within that time frame... some teams may start out really bad and get really good by the end of a long league which throws out comparative results.