Balancing lines by handedness is sound but I'm of the opinion that the lines should be balanced by defensive ability, unless Yeo can somehow manage to get the entire team to check as consistently and relentlessly as Vegas did last season.
There's enough natural defensive aptitude in the lineup to limit one defensively deficient player per line. "(d)" - designates the defensively deficient player. It just so happens they'd all end up on the right wing, here, but wherever the wings play the principle should stand:
Schwartz-Schenn-Maroon/Fabbri (d)
Perron-O'Reilly-Tarasenko (d)
Steen-Bozak-Thomas (d)
Jaskin-Barbashev-Fabbri/Maroon (d)
Soshnikov
I really hope Barbie can learn better FO skills from the new arrival center men. Thomas is given a "d" until he proves himself at the NHL level, which remains to be seen. It's possible his lax back checking in the CHL playoffs was injury related but from what I saw it wasn't up to snuff. Fabs also has something to prove in that area. Maroon isn't so good either, and Vladdy rarely picks up the open man in the D zone or checks anyone closely.
Just my 2 cents and I'd much prefer a relentlessly checking team mentality but I have my doubts that certain Blues forwards are capable (Vladdy in particular).