For whatever reason, you cannot make units play animations from an init field. I have no idea why, but it sux. One solution is to make a one line script that you run in their init field:
[this, "anim"] exec "switchmove.sqs"
Switchmove.sqs:
(_this select 0) switchmove (_this select 1)
Another thing that MIGHT work is to put this in their init field:
this call {_this switchmove "XXX"}
I know I've tried that before, but I can't remember if it works or not...