Russia and China will take the side which has more money and will buy more from them, they are already selling their weapons to Saudis and wont compromise their sell by some small purchases, no need to mention the U.N resolutions against Yemenis.
Yemeni's only friend is Iran, but for your own reasons you prefer to alter the reality!
Like the four Iranian drones which were advertised as their own products.
unlike you, I wont presume Yemenis as complete liars just to prove my point.
just like our car industry which assembles foreign cars and advertises them as our products, Yemenis are doing the same, even Turks do the same with their military products.
unveiling of these systems has a more important message for their enemies.
the system which they used to shut down those birds.
They didn't have missile program, they just had missiles, like the rest of lazy Arab armies.
we had scud missiles and we weren't sure if it would miss the city from 300km away, let alone targeting a specific part of city like airport from 1000km away, this capability is way beyond them.