I say “no offence”. And this is impossible to be “Czechs are more Slavic than Belarussians” such as impossible to say “Serbs are more Slavic than Poles” becouse it would be nonsense.
Come on people, do you really think that Russia can be fully Slavic land with the millions of contacts with Tatars, Mongols, Germanic ruler dynasty Romanov, Cuman mixed Rurikid rulers… but there is “nothing bad” in it. They did what they thought it’s best for their country.
Same situation with the Czechs. Even they know that they have siginificant Germanic influence such as South Slavs have for example Albanian (Serbs) and if you want to say Ottoman (not in genetic sense but in the loanwords).