Fico get all the free shit from Europe to build his country and a boat load of free money from his personal investments in shady businesses, so in that case he does get both upsides.
ceding sovereignty and to many degrees cultures to another nation to kinda like be a vassal state is quite literally not thinking about your nation first lmao. even less so when the other nation funds your political ascension, like.. that's the opposite of thinking about your nation first. that's flat out doing it for the other nation man.