Kurds. Give them kornets and igla-S as well as a shiton of lancet suicide drones.
It's time for russia to send weapons to nato enemies.
Sell Yasen-E to China. Sukhois and pantsir to Iran.
Important that it only hurts the US and EU though... giving Kurds weapons would end up being used against Turkey and Assad in Syria or Iran, and they clearly are not the enemy.
I would say the best thing they could do is get the houthies and Saudis to sit down and work something out they both might be, if not happy with, at least both find acceptable to stop that brutal and costly war, so the west stops making money selling more bombs and missiles to the Saudis.
Welcome Iran into Eurasian trade groups... and ask Saudi Arabia if they want to join.... middle east is not Africa or Europe so it must be part of Asia...
Get them focused on trade and making money... don't bully them with threats but make it clear trade would be better without war...