One man's take:
One of the more anonymous positions on the field, many of these nominees never got the "name" recognition of their brethren, but provided solid and steady play and paved the way for some great running backs in their time, and in some cases displayed great durability. Working alphabetically:
Bastaja - the most decorated of the guards with 6 divisional and 2 league all-star nods, and only one of two Bomber guards to win the Schenley for outstanding lineman in the CFL. Along with Black, Bonk and Walby, was part of a ridiculously strong o-line in the mid-80's that helped Willard Reaves become a star.
Black - an ironman with a bit of a nasty streak, he anchored the line throughout almost all of the team's last great sustained run of excellence.
Bond - two great years, but left for greener pastures (both in terms of money and uniform colour) and doesn't have the mileage of some other candidates
Brown - effective in his half decade here, but his efforts could not translate into team success
Butler - the other Schenley winner in the group, he was dominant in his time here, and also in his other league stops (not to be factored in) and considered one of the best linemen in the CFL, regardless of position. Only his smaller sample size in Winnipeg keeps him from top two consideration
Ceretti - part of the original Bomber dynasty in the 1930's-40's and the most tenured candidate with 16 seasons under his belt, and if Vince Leah ranks you among the best ever, that's heady praise
Kotowich - not sure if you want an o-lineman who has a "nice guy" award named after him, but his legacy in this city is very strong indeed
LaBatte - the best lineman the Bombers had during his time here, and it took a while to recover once he left via free agency. Loses points for ditching us for the 'Riders.
Lear - enjoyed the first taste of Bomber Grey Cup success, and made his name later as an NFLer and Stamps head coach in that perfect 1948 season.
Lueck - two good seasons, but too small a sample size to contend here
Mogul - in the group with Lear and Ceretti in the 30's, albeit less feted than the other 2
Patrick - a big part of the 50's-60's dynasty teams, playing both ways, and logged more games than any other candidate. Also won more Grey Cups than any other, blocked for Leo Lewis, and the only lineman in this group to get an Outstanding Canadian nom. His civic legacy and family tree put him a level above for me.
Piper - Patrick's partner, matched his all-star numbers, but was never chosen as the team's best lineman like his teammate was
Sheridan - the guy you'd most want on your side in a barroom brawl, no all-star nods, injuries and a sour departure hurt his standing
Thorson - picked up the slack for Patrick and Piper when they retired, but could never reach the same level of team success they had
In the end, it's Bastaja's awards and Patrick's family legend that clinch it for me. They are my top 2.