As an alternative you could create your own random animation.
Create your random animations as "character animations"
Create a "called by other action" action:
set a random value A between 2 sec and 5 sec (or whatever your time intervall shall be)
pause for A sec
set a random value B between 1 and 4 (or as many different random animation you have)
if B = 1
play animation 1 (and wait)
else if B = 2
play animation 2 (and wait)
...
end if
jump to actionpart #1
And call this action at the beginning of the scene or whenever you want.
(instead of setting the animation to wait you could call the action again in the last frame of your "random" animations and get rid of the jump to actionpart action)