Not really, no. You said he's basically making Russian tanks that are invading Ukraine.
He owns less than a third of a company that makes steel. In Russia. Because he's a Russian. The article says the tanks are, and I quote "almost certainly made from Evraz Steel"
So there's no evidence they are. There's also no evidence that Roman Abramavic has anything to do with where that steel went after it was manufactured.
Did you know that the American made SR71 Blackbird was made from Russian titanium? Yes, the SR71 Blackbird, a plane built in the cold war to spy on the Russians, was made from titanium from Russia. Obviously Lockhead nor the US Government went to Russia and said "Hi Sergi, we'd like to buy some titanium to build top secret planes to spy on you"
That titanium went through multiple purchases long before it ended up being turned into spy planes.
Also, this article quite clearly says Evraz have lost a fucking fortune. Why on earth would a business man willingly want to help a military action at the cost of billions to his company and himself?