I think this get's a nomination for mistype of the year!

I use Kats as a last ditch kind of thing. Just keeping a single unit behind the lines and if things get really hairy, Lancers breaking your line apart of somesuch, charge them in. Even with the negative factors from being packed in with your other troops, they usually clear the line of it's problems.
The Pron I use as normal heavy cavlary. Engage other heavy cav, flanking attacks etc.