I'm also an introvert but I find that Russian girls are very forgiving of it, sometimes even giving preference to that personality type. After saying that, "introvert" does not mean vagina-man who lives in his mother's basement at 35 years of age. Russia already has plenty of guys like that, and the girls hate them. Putin is the classic example of a strong-but-quiet personality who can do much better in Russia than in other 'European' countries.
I think some extroverts would probably struggle in the North, because I often hear girls up here say that Italians are too "emotional." Another reason is that they really look down on stupidity. For example, guys whose game is to play the dumb clown role (like Jim Carey) would probably struggle.
Blaming Russia/Ukraine is IMO just a cover for some kind of personal issue. Take a look at some of Courage Reborn's threads for proof... he landed in Kiev with 0 cultural understanding but was absolutely killing it within two weeks. From what I gather, he's methodical about it, puts in the time and effort to pipeline and cold approach, and as a result... gets to smash prime pussy.
I find that online + social circle (combined) works well for me, but you have to know which sites to use and it varies from one city to another. It's also not very efficient when compared to cold approaching, but I have no other way to burn my free time while I'm watching the money markets.
Mamba was good in Kiev a few years ago, but I'm not sure now. In other cities (e.g.. SPB), 99% of the girls on Mamba are looking for P4P in some form (prostitution, sponsorship, holidays, serial daters, etc.), so it's a waste of time in that city.
I found my main girl in Kiev a few years ago on Mamba... (she's Armenian, in case anyone was wondering)