It's more out of curiosity :
Mounted PA cost 28 points
CL cost 25 points
CL may not evade
PA may evade and be used in melee
Both may inflict "Shatter" , both need open terrain
My real question is why may mounted PA evade while CL ( and DC ) who also may shatter so is a very agressive weapon (and characteristic ) may not ?
To mee it's a huge advantage for the mounted PA who I admit is not good vs infantry ( impact )
The claims are materially different in the charge and CL are much better here.
CL +2 in the charge against anything unless the usual exceptions.
Mtd PA no claims against infantry, +1 against mounted other than CL and LSp.
Mtd PA then get +1 in melee so they are better there.
Evade (if they have a suitable missile capability of course) because it seems to fit the way the troops operated. Although it is fair to say that Mtd PA is a bit of an oddity in a few ways and you could probably drop it from the rules to no ill effect and use other classifications to do pretty much the same thing.