Now you need three managers. The reason for the 20 person standup is to save money and give lip service to the standup trend.

Same manager with right-sized stand-ups wouldn't cost anymore money, unless that manager is making many multiples over what any of their team makes. It seems more like a kneejerk reaction to not "waste" the manager's time at the expense of the actually-more-important-but-hierarchically-less-important employees.

Easy. Have another team member run the stand up.

Again the problem is that no one is interested in processes to make things better or more efficient and then people blame the process.

The process might have plenty of short comings, but we’ll never know.