Last time I played a DK cleave did use the weapon damage type. Faith malforms have little impact, because Cleave damage has always been like charge/Mounted charge, independent of weapon average roll, just weapon damage type. Getting a vuln weapon to cleave always has been a player-skill rewarding factor. Like the air axe, or Fire Lance, or Ice sword or Blackwatch sword. Not to speak that Faith malforms are one of the wrost malforms compared with the good one, unless you you happen to be some thing about fighting undead.
If I log on one of my DK's, I check for you guys.
Won't comment on Crusader "charge" but if you have a crusader you can test this very easy.
Charge from what I know is still good old bash damage type. That would be a >>> ANNIHILATES <<< vs good old gnomes mobs.
I mark mounted charge at ~175 HP and cleave a ~225.
Hahaha, remenber our Halloween halfling cleaving testing @Magick. What year was that?
But UC has a good point. Is it worth to charge when you can do better damage with a vuln open round?
In my opinion charge is a utility tool, best used as surprise opener for lag. Or to lag a fleeing mage. The point being a insane HR/DR meele will do better with murder, for most of us common mortals charge is an 95% chance of Caps damage that isn't cut by armor.
So if you are fighting some 1000 AC mage, or a non counter defensive meele, you might value charge.