Not really Vinstor. The swordsmen might lose less on the charge, but so too do the Cav, AND against really good cav, (anything with an 8 charge stat), the Swordsmen will get hit with the full effects of the formed charge.

I’m not sure But I think units when braced with shields/spears inflict a "hit" on anything that runs into the shield/Spear as a kind of Shield Bash Attack. This means that even militia spearmen vs. Mailed Knights results in every knight who contacts a spearmen taking 2 Attack 19 hits each, (that 5 basic, 6 for the reflection, and 8 for the Spear_Bonus). This also means Shield Units are inflicting a Single Attack, this seems to slow the knights down, although it rarely stops them totally. Weather the shield effect kicks in seems to depend on the total defence, comparative to the charging attack of the opponent though.

This is also probably why 2-handed Swords have so many issues with Shield units. Since the Swords don't normally have the AP stat the shield effectively nullifies their charging effects by doing a knock-back on them.