I had this idea for Bretonnians. Instead of having clunky rules for unit formation, let them use normal unit ranking up and allow them to cause disruption on the unit they charge. On the first turn only.
As Bretonnian Knights thunder into the enemy they adopt what they call Lance Formation. They form a wedge as they charge in, that penetrates deep into the enemy ranks. As having enemy knights amongst your ranks from a frontal charge is very disrupting, the Bretonnian Knights cause Disruption on the unit they charged. If the Bretonnian Knights do not qualify for disruption, 2 ranks of 5 models on the flank or rear, the disruption only lasts for this round of combat.
However you word it this is the idea I came up with. It gives Bretonnian Knights a bit of combat resolution punch in the first round of combat.