In the days when i was starting with livebearers and had little tank space, i used to have 30-50 swordtail fry, from multiple females, in a six week period useing the trap method. so it deffinatly is possible, but in saying this i did tend to lose a female or so becuase of stress.
Now with more experience i would say to you, plant the tank heavily, feed the fish well, dont stress at all, before you know it, more fish than you know what to do with.
Shae