It's not like Iran needs divisions worth of volunteer Russian/Chinese troops in order to fight. They have plenty of volunteers from the Muslim world.
But Russia will surely be helping guide Iranian fires, and Russia can easily leverage China into covering up what shortcomings Russians themselves don't have. And then there's the matter of unlimited drones/small arms/ammo for Iran.
At the most minimum contribution level, China would still do it's thing of selling dual use small equipment to anyone. They did this for AFU and RUA in Ukraine. They'll do it for both IDF and Iran. And imho like what we've seen in Ukraine, the boost is stronger for the side that has less airpower and conventional force.
Rationally, both Iran and Israel lack the clear cut strength to take on eachother, however, do they really have the rational behavior to understand that?
If they did, then a Hamas-Israel ceasefire would be the best plan. Hamas proved that they are Palestine's best fighting force and would surge in recruits. Israel gained blood vengeance for the dead and can try to purge all the incompetent in the government/military.
Hell, if the Likud is purged in the aftermath, it may even be a development that contributes positively to Israel's long term diplomatic prospects and lessens the chance of Israel being collateral damage in the cold war.
Everyone can get something positive out of the current situation if they think rationally.
