In Smash 4 Lucario is top-tier and has stayed there. Link has fluctuated between top and mid. Plus, you can easily dismantle Link with any reflector move or consistent shielding. Lucario has an incredible and reliable projectile, meaning he can put decent pressure on at range, and keep himself safe. Should an opponent approach, Lucario has many out of shield options, including a very powerful grab and reliable jabs. Should Lucario be forced to approach, he has an unpredictable D-air and even some crazy Extremespeed shenanigans. Link lacks in reliable approaching options, and needs to be forcing approaches. If Link faces against any good Spacies character or even Palutena, Link needs to rely on close-range options. If Lucario vs Link, Link would have to approach, because his projectiles won't KO, and Lucario gets Aura buff + rage effect. One Aura Sphere with those buffs will cut through anything Link can fire, shoot or throw. One simple Double Team from Lucario when Link has to approach will easily cause Link to fall apart. Nothing against Link, but in Smash Bros terms, Lucario has the upper hand in this match.