Indeed it isn't a general solution, it's just really good for almost all board games. Your example is one that it's not the best for and you could use a differ

Indeed it isn't a general solution, it's just really good for almost all board games. Your example is one that it's not the best for and you could use a different approach or amend the approach to take a payload for some actions and have some client smarts for those actions. Although even in your example of 50 units with 50 moves each, having 2500 moves is certainly not a disaster in a game where the server only does work in response to a player's move and players don't take multiple moves per second and more likely take seconds or even minutes between moves.