Your list looks fairly solid.
Normally I would avoid the repetition of weapon loadout but for Cawdor I would make exception for brethren with the Blunderpole. It is just too cheap and good not to have a tonne.
I would drop the cherub although a good choice later.
You can have a specialist at gang creation. It costs nothing so do it. A Specialist can choose thier advances rather than randomly rolling which is just better. They also can take the special weapons on thier list which can add a bit of pinch without the extra 45 credits of a champion.
If you pick a Brethren Specialist run him/her with a Long Rifle. It gives you a fairly decent long range weapon which otherwise Cawdor are a little lacking aside from the firebrand wordkeeper Heavy crossbow.
Do not bother with the combi autogun or flamer. You can get three blunderpoles for that price which set people on fire just as well as the flamer. The Combi autogun has Unstable. Bleagh. No blaze weapons really compete with the dirt-cheap blunderpole for the price.
I would however not get a brethren specialist when the Redemptionist Brethren specialist is available for only 5 credits more. They can have shotguns, which initially compete with the Blunderpole for reasonable utility or the price and then you can get special ammo, both the ones on your list and others (ammo is not a weapon, do you throw the bullets or have the shotgun).
The Firepikes AP and Rending makes it more of a viable weapon in the land of the blunderpole.
The important weapon however is the grenade launcher. Hard hitting, decent range, crowd control and with interesting ammo. What more could your trash bois ask for?