Well first of all the stingray command has a Russian accent. Second of all they are all over the world and have a leader. If it's possible their leader COULD be Russian but not all the soldiers have that accent. Except for their warden she Linda sounds Russian. Then there's the vehicles some of them have a Russian name like urga pustulka. I could be wrong on this one but let me know what do you think.
I doubt that. I am myself Russian (Donetsk for that matter to be presice, but still) and for me, Stingray dispatcher (By "command" I believe you've meant the Dispatch?) sounded solid British. In fact, his voice even reminded me of the Hellsing organization dispatch in English dub. And yes, GMRE is right - the Lacrima control station guy sounds more like either an Australian, or South African ("Boer ")
Sure one of the Wardens sounds Russian, but I see no other indications that their central command might be in Russian Federation. It would be wise for Russian government then to use Black Hand rather then GRU officer in Panau as part of the shadow operation. And as for vehicles - in JC3 they just use the same vehicles as Medici Military does.
So personaly I don't see why they might be Russian-based/centered organization. I think of them more as a multinational corporation with central HQ in Australia or other non-alligned, neutral but highly developed country.