What last Big knight for my infernal lance?

Hey guys! Im making an infernal lance list from the houndpack lance, which will be 8 wardogs (2 stalkers 2 brigands 3 karnivores 1 Moirax) and two big knights. One of which is a rampager, which i hope will draw a ton of fire and help my little knights get left alone. Im looking at a few options for the other big knight spot, namely the Tyrant, the Castigator, and a twin gatling despoiler. I know the tyrant and the despoilerwill be a lot of guns, but the castigator also gets 18 shots at range with twin linked so not too much worse of an output than a despoiler, with the much added upside of being very capable in melee.

What would yall choose?