I'd been wondering about this myself. I made a little group of the series 7 Evil Knight, and had been hoping to do the same with the heroic knight.Brutus and his Boarhead Elites
, on Flickr
To me the problem is the Heroic Knights visored helm. I don't mind it for a leader, but I wouldn't want a block of knights all wearing them. Before series 9 was released I read a rumour that the knight would have a silver version of the Evil knights helm, which would have been a nice piece in a new colour, and looked pretty cool as a group I think.
Mark of Falworth sprayed one for his CCCX entryhttp://www.flickr.com/photos/mark-of-fa ... 224726303/
The heroic knight's current helm is light bluish grey, but there aren't many other helms in that colour, not that look suitably epic anyway. I'd be open to using a custom helm, so I have thought about spraying/painting one silver like Mark did, or even a 3rd party helm.
My suggestions would basically be to keep colours similar, switch some faces and add capes, weapons etc. Much of which you've already done
Less talking, more MOCing.