The Perry's RN Gardner gun & crew would be my choice. Slightly different uniform to your Russian chaps, but also slightly smaller than Redoubt. I know there's a lot of lead there, but any extras in the sets would come in useful for 'Nef crews, signallers etc. Sell the Redoubt guns & crews and you then don't have such an excess of weaponry.
Or..... there is always the Russian Navy Maxim crew from Copplestone
Maybe too out of period, but rather nice. Alternatively, if you wanted an army crew there's this one

That's a dilema I'm facing at the moment, as is what weaponry they should carry. I'm intending only a single machine gun, maybe a Nordenfeldt or a Maxim. But then I need a figure to fire it either turning the crank (Nordenfeldt), or holding the pistol grip (Maxim). I did invest in a bunch of Redoubt Russo-Japanese War figures manning a Maxim (I only bought the crew figures), but they turned out to be huge. I don't really want to buy 6 packs of Perry Machine Guns, and I'd like a change from the usual 'naval figures manning steam contraptions' trend.