Argument Critical thinking philosophy math probability

Question

Is this argument strong or weak? 

Jimmy and Eric are both musicians. Jimmy is an expert guitar player, so Eric must also be an expert guitar player.  

Answer 1

J & E are M

J is M

E is M

J is G, a subset of M

E is therefore in G

is a very weak argument

yet it's better than it would be.

the larger G is as a ratio or subset of M, the stronger (or less weak) the argument

as G/M approaches 1, it's a near certainty and nearly conclusive argument

Socrates would not like the argument, either way though. He was picky. Plus G/M is likely to be a very small fraction, far from 1