I think I understand this now.
Sadly it doesn't offer me the kind of control I'd would have liked to have. Given that the animation offset is based on the grey values of the static map, the delay between objects isn't big enough, if the area is pretty large and the objects next to each other almost share the same grey value. I thought maybe with the now added effects tab there might be a few other options to trigger animations. Guess I'll have to find another way to do this.
I know this isn't something forest pack was made for, still it would have been very convenient. Nonetheless thank you Michal for the help and effort!