It's a very small army and a very expensive(all metal). You'll have a very hard time against horde armies or against armies with lots of war machines. A well aimed cannonball can destroy your only hard-hitting unit.
I've never read that youl like cavalry armies, I'll post some other possibilities:
1. Classical chaos warband:
exalted champion of Tzeentch (mark, cheap magic weapon or armour) = +/- 200pts
15 chaos warriors (command shields) = 270pts
5 knights of chaos (command, mark of Tzeentch) = 235 pts
20 marauders of chaos (command, light armour and shields) = 170pts
4 screamers = 132
2. Marauder clan:
exalted champion (mark of Tzeentch, disc, cheap magic weapon or armour) = +/- 245pts
aspiring champion (battle standard, chaos steed) = 120pts
24 marauders (command, light armour and shields) = 198 pts
24 marauders (command, light armour and shields) = 198 pts
9 marauder horsemen (command, shields) = 165
12 warhounds = 72
3. Fast army: yours
4. ...