You're comparing diesel to PV which doesn't speak to the merits of PV vs centralization. There's also the massive disadvantage of fuel distribution from diesel, which is a form of centralization and bottlenecking, and then there's fuel shortages and costs which PV doesn't have to bother with.

Also is Russia targeting individual PV systems? That's tantamount to targeting individual residences which, if we're granting that, there's no amount of decentralizing that would ever mitigate those attacks so diesel vs PV would be moot.

Lastly I don't think that's what greenwashing means. Greenwashing isn't representing renewables favorably, it's tying some external negative practice to language of environmentalism with vague buzzwords and questionable claims of environmental benefits to make that thing look better. But in this case there's no external thing being tied to environmentalism, we're just talking about PV directly.