Ukraine ping
The Russians could have used illegals (i.e. SVR employees without diplomatic cover - or immunity) to do this. That they chose to use an amateur suggests they’re not exactly flush with cash to train and maintain illegals abroad. If they don’t even have the budget to do this in the US, Russia’s biggest likely adversary, chances are this ain’t your granpappy’s all-singing, all-dancing KGB.
I think you are a missing part of it. The FSB/KGB/NKVD was always the Fredo of Russian intelligence. If the GRU did, he’d be dead. and we’d never know about it.