I can't imagine a Mussina statue even when he makes the Hall. When I hear the name Mussina, I just don't think Orioles legend like I do with the other 5.
Not gonna argue bWAR is the best stat to look at for something like this, but it's a decent one.
Moose trails all of the others in career WAR as an Orioles except for Frank (who only played 6 years here). He's comparable in WAR/year for all of the rest (except Frank, who amassed a crazy 36 WAR in his 6 years here), if you want to think of it in terms of individual greatness while an Orioles, but he obviously falls well short in terms of time spent in Baltimore compared to all the others so he loses ground in longevity.
I do think it's a good test case, as there is nobody else remotely close to Mussina. If Mussina is in, and if Mussina gets a statue, there wouldn't be any sort of slippery slope concern.