I was only referring to their profiles, since the purpose of the original post seemed to be projecting future value.
Alomar was a career .300 hitter and at the height of his powers had gap power to all fields and strong control of the strike zone. Because of his swing and profile, Biggio may hit .300 in individual seasons, but he will never consistently hit for average like Alomar. Conversely, Biggio's patience is elite and he has more power than Alomar, again due to his fundamentally different approach.
On the bases, Alomar was a high-volume burner while Biggio is a highly efficient baserunner with solid average footspeed. I can envision Biggio providing similar value with his legs as Alomar without the benefit of 50 SB. Again, completely different tools/profiles.
With the glove the two aren't comparable. Alomar was an all-time great with lateral range in both directions and the arm of a shortstop. He was basically Robinson Cano without the steroids and more acrobatics. Biggio is fringe average and just doesn't have that physical firepower. With his baseball IQ I wouldn't be surprised if he continues to improve his D, depending on how much autonomy he has with positioning.
Biggio and Alomar have very little in common other than they both played 2B for the Blue Jays. I'm not saying Biggio isn't capable of putting up 6 win seasons (he can but probably won't). But if he does, it will be with a drastically different offensive profile.
Like I said, a Biggio career year probably looks more similar to Chase Utley (later career start, great power, eye-popping value on the bases without being a burner, etc.), but even then the comp isn't great.