As an Isengard player, I've been building up a scout force for quite some time now. The offer a nice “skirmishy” feel to your games and it’s a nice change up from the regimented Uruk warriors.
For objective based games I usually throw in the scout drummer. 11 inch movement is beast (Marauder upgrade + drum) and you really feel like you are controlling the board. For games based on a lot of killing, I usually toss in the scout banner and flank.
Both types of play (rushing to objectives + flanking) highlight how it’s always best to avoid charging head on into enemies.
I agree with a previous poster: they aren't entirely effective on their own.
As I've always wanted a mob troop type for Isengard without purchasing Mordor orcs, I've had success tossing a blob of Wildmen into the fray while the scouts dart along the sides and flank/take objectives.
It’s awesome to see the marauder + wildmen combo on the board: Burn every village!