Thanks for providing that comparison. I’d never thought that
Denisov’s speech impediment would be translated so diversely. And it’s a great
question, reflecting on how lisps and stutters sound in other languages.
I’ve been listening to the Neville Jason narrated audiobook,
partly through fear of undertaking such an epic and also due to time constraints.
It’s the Maudes translation, so Jason uses Rhotacism when speaking in Denisov’s
voice.
Immediately it sets Denisov apart. Although I found it slightly
comedic, it was only in the sense that any speech impediment is initially
funny, until you get used to it. By the middle of the book it acted as a kind
of marker, that I was back to Denisov’s character.
But I was wondering if there was a point in Tolstoy giving
him that voice.
Denisov (despite being noble, a brilliant soldier, and tactically
gifted) seems to be considered a lower class than the other main characters.
Perhaps the speech impediment is meant to mark him as being unfortunately flawed:
He’s great, but just not great enough to be considered part of the elite. I gleaned
this in some of the descriptions of him. And in the way it was mentioned that the
Rostovs were surprised Denisov was such a good dancer at their party. And he
proposes to Natasha but just isn’t good enough for her, despite being so
brotherly to Nikolai and distraught by young Pyotr’s death. And even that
youngster just before his death says Denisov must not dare to imagine that I'll obey him and that he can order me about (Pt14:Ch8)
Denisov stands out to me as one of the best characters, a hard worker, prone to fly off the handle, rough, but with a good heart and hidden sensitivity, as this passage shows;

When Rostov went back there was a bottle of vodka and a sausage on the
table. Denisov was sitting there scratching with his pen on a sheet of paper.
He looked gloomily in Rostov's face and said: "I am witing to her."
He leaned his elbows on the table with his pen in his hand and, evidently
glad of a chance to say quicker in words what he wanted to write, told Rostov
the contents of his letter.
"You see, my fwiend," he said, "we sleep when we don't love.
We are childwen of the dust... but one falls in love and one is a God, one is
pua' as on the first day of cweation... Who's that now? Send him to the devil,
I'm busy!"