Man, i've been growing AF AK47 (Grassomatic).
Two out of them seem like yours, the little ones. Another 4 are sweet and 5 times bigger. The other one looks fine, except that the leaves are weird, kinda like a mostruosa.
So i guess you're not doing anything wrong, but some seeds are worse than others. I have four good ones, a crazy one and two small replicas. Like bonzais. I don't expect them to reach the same size as the genetic superior ones.

From seed - oct. 24.
under lights (400w) - oct. 30.

Please send pics. I'll post some as soon as i get the cam.