Balance Clash separately from Solo Queue. And have a mode where people can practice Clash games with those type of balances.
Because you will have data on what works really well and what works really poorly in a massive 5 v 5 style tournament. That directly affects everyone outside of the pro scene.
If X champion has a 1% play rate with a 33% win rate, balance that champion FOR CLASH ONLY. Because I think it will be hard for Shaco's to be good in a organized setting. But in a Solo Queue setting that champion is really annoying. This is just an example.
It would be extremely foolish to try to balance THREE THINGS in one sitting.
Pro Play, High Elo/Low Elo Solo Queue, Non-Pro Coordinated Play. Just the first two clash with each other a bunch in champion cases like Ryze, Cass, etc. Adding in a third balance system will make it even worse.