Let's see if they actually do that and how it might work out. Seen it attempted several times with reserve teams but have yet to see it work out successfully. What ends up happening is both teams and the reserve or 2nd team suffers, players and parents get pissed, some jump ship and the whole thing is a cluster and then it's back to normal sooner or later.Your statement about nobody is going to shuffle players around each week doesn't make sense. Surf has already stated that they're moving to pool play. Working from the pool on a weekly basis + trying to define the best player combo to make the win is exactly what they intend to do.
The only piece that isn't clear is if clubs will sacrifice ECNL performance to boost ECRL when needed. But why wouldn't you if a couple of ECNL games are "in the bag" and the end goal is to always win. (Maybe you wouldn't want to risk your top team losing to a poor top team.)
Having a different lineup with different players each week normally doesn't make for a happy group of players who count on, rely, and pull for each other. Maybe surf can make everyone happy but I will believed it when I see it.