Some info (specs / manuals) on the Piko units would be good before we completely write the idea off. While JRad is correct the AM-1 is designed around small scale point motors (snap ,Tortoise etc) that doesn't mean the AM-1 can't be used to drive something than can handle large scale, eg instead of AM-1 -> snap point motor you could have AM-1 -> Capacitor Discharge Unit -> snap point motor.
Update: After finding the specs for the Piko switch machine it runs at 18 to 24v so you wouldn't be running both an AM-1 and the switch machine off of a single battery and you wouldn't be driving the switch machine directly from the AM-1.
- Tim