Love the previous suggestion of Arkady.. Though guess it may be a bit rhymey with Matvey..?
Also think Nikolai a good option as another exotic version of common English name.. Nico is cool too.. As is Pascal though I prefer the spelling Pasqual
These suggestions are all men/boys I know or have met in real life
My picks for you.. All names of boys/men I have met in real life..
I like the suggestion of Pascal! How about Dominic nn Nico or Nick?
I really like Roman and Silas.
Hmmm... I would stick with the Russian (or at least exotic) theme... I love Anton, Dmitri, Roman, Pavel, and some of the others listed. Sorry for any repeats...
Lev (This would be awesome)
Konstantin (awesome name)
Laurente (very nice)
Tamryn (maybe a bit similar to Cameron?)
I like Ruslan for a Russian name that is not obviously Russian (or it wasn't to me, when I met a boy named Ruslan). I also like how it doesn't repeat any of Matvey's sounds. To me, Alexei, Vladimir, Fyodor etc are very obviously Russian and you said you didn't necessarily like that.