Since outriders are move or shoot anyway, why not put them on barded warhorses? Since they will be targets, the extra 2 armor will help alot. So they would be a 4+ armor save right? put five near the middle of the board so they dont have to move far and blast away. Add a priest with a Doomfire ring or Dragon bow in for Hatred if they get in CC and to give the champion re-roll to hit and to wound with Hammer of Sigmar prayer and they get nastier.
Outriders are in my oppinion mobile handgunners.
What makes them able to compete with handgunners are aspects of being fast cav combined with the repeater handguns that give them a narrower frontage.
Fast cav advantages that are important to the outriders:
The ability to move after a voluntary rout.
The ability to fire in 360 degrees.
Without these the handgunners are no longer superior to the core choice that is handgunners in my oppinion.
With these however, the outriders can take the form of flank guard, shooting up fast cav trying to outflank our ranked up units and run like hell and redeploy if they should encounter dangers they can't shoot down.
I for one, am not inclined to pay points for loosing these abilities in order to get an extra point of saving throw.
On the general debate I would say that it depends on the rest of the list.
I do see both units being capable of working in both defense and attack.
But I see the outriders as a more defensive tool and the pistoleers as more of a counter-attacking/attacking unit. Thus they are not in competition with each other, if we overlook that they are both a valuable special choice.
The units who can perform the pistoleers tasks should they be left out: captasus, huntsmen, vanilla knights.
Ditto outriders: handgunners/crossbowmen, mage-power, artillery.
And the pistoleers do suffer -1 for stand and shoot actions just like most other units.