Everything you typed after that is irrelevant based on my experience. Prepare for the silent steely eyed gaze from parents despite your best efforts to even the teams up. You just can’t win being a parent coach. Are the two best field players the best strikers or overall players? If best strikers, did you by default put the best defenders on the same team with the best GK? Just trying to spitball on what might have unintentionally happened. Also through my decades of playing, soccer dad-ing, and coaching (not my son!), outdoor soccer and futsal are two entirely different games.