We should have a stronger representation than that. Those figures would make sense if there was a world golf tour managed globally; not separate PGA and European tours (not to mention Asia tours or others). After all, those rankings stem from the predominant tour (PGA) being played on American courses, many that have a long history of tour events. We should be more competitive than we are.
PGA and Euro Tour events are counted equally in the world golf rankings.
Again, as I have noted before, where are these Europeans that you're talking about? Golf now--as it has always been--is dominated by the UK and the US; there are good players from former colonies, but that's always been the case. You are just seeing more of them now because travel is easier now than it was in the past. Players from far-flung countries can now more easily play more majors on US soil.
To wit: there is one good European player, and that's Kaymer. Other than him, please name one consistently good European player. They simply don't exist.