Three days left until Open War and I still can't stop thinking about my list even though it's all been finalised. I'm still not totally convinced by the Vindicator and the Dreadnought. In the end I got to thinking about Thunderwolves and what I could run if I dropped both of those units. Hmm, that would be 255 points...
Wolf Guard Battle Leader, Thunderwolf Mount, Wolf Claw
5 S5 I5 Power Weapon Attacks on the charge with re-rolls either To Hit or To Wound. Nice.
Thunderwolf Cavalry, Thunder Hammer, Storm Shield
5 S10 on the charge with a 3++ save. Also nice.
That actually leaves me with 10 points to spare so I'd probably give them both Melta Bombs as well. These are both designed as counter-charge units, they can hide behind my Razorbacks and then pick their targets with their 6" move, Fleet and 12" charge range. They're not super-killy but they are good enough to add a dedicated assault element to my army.
Obviously, another option would be to keep in the Dreadnought as he adds a useful tarpit against horde style armies and then just take the WGBL without the Melta Bombs instead of the Vindicator (and also dropping the Rune Priest's Saga) He could prove to be really useful against small, elite Assault units such as Sanguinary Guard.