Lore question - How "strong" is Chapter Master Calgar ? or how strong was he supposed to be ?

[Hoenir;]

He is the guy. The Defender of Ultramar, the lord of Macragge and Chapter Master of the Ultramarines, only Guilliman outranks him.
Couldn't his arrival at the end change the battle just by him being there ? I thought that, the arrival of a chapter master meant to be a super huge deal.

[oh my god, I love gay people!]

He is an important blueberry,thus he is god

[Phreaked]

idk anything about the lore but just based on playing the game he is one bad a$$ character!!