1500 GK force

I’ve made a few lists, so apologies if I’ve made one too many, I just like to solve problems and use my imagination in my spare time.

So here it goes:

Librarian w/warding stave, shrouding, sanctuary, warp rift, might of titan (goes in LLR)
Brotherhood champion (goes in Rhino)

Purifiers (5) w/ halberds (5) (goes in LRR)

Grey knights (7) w/1 pyscannon, halberd (5) in Transport: Rhino
Grey knights (5) w/1 pyscannon. In Transport: razorback w/pysbolt ammunition
Grey knights (5) w/1 pyscannon. In Transport: razorback w/pysbolt ammunition

Land Raider Redeemer w/pysbolt ammunition, multi-melta
Grey knight dreadnought w/ pysbolt ammunition, 2 twin-linked autocannons
Grey knight dreadnought w/ pysbolt ammunition, 2 twin-linked autocannons

Basic formation:
LRR leads assault closely followed by the Rhino.
Both razorbacks provide cover for both the dreadnoughts to provide fire support.

Weakness: AV14 is a problem until the LRR and unit inside has a charge range.

I'd be tempted to change the dreadnoughts to:
Grey knight dreadnought w/pysbolt ammunition, assault cannon
This would give them more of a jolly feel, does anyone do this and have success?