I dont think he will get near prime Vidal in terms of tackling and being one man army.... but he shoudnt anyways, as that Vidal was very, very unique.
What Lemina seems to have over even prime Vidal, is that this guy is technical and thats a big plus because is what we sorely miss. He is technical but has a fair share of tackle and stamina on him, so he could be very very useful in our midfield that badly needs technical players and less of gattusos.