Also depends on the type of 4-3-3. Germans play very direct with high pressing. Against Barcelona, even with a 4-3-3 it is different because they're anything but direct.
You win against Klopp the way that Allegri did. Give them the ball, sit back, and look for holes, which is the opposite of how you play against Barcelona because you will be pinned for 90 minute. If you look at Liverpool best games this year, often possession is equal or they have the ball less. For their worst games? Against teams that play deep.
Madrid will beat them if they play.