QUOTE
you can still do the 4x speed thing but youll have to do something about the marines.
Just change the marines to ghosts or give marines long range. Ghost have the longest attack range anyways (longer than goliath). That's actually not much a problem since an upgrade marine range and a ghost range are nearly the same (with ghost slightly longer). So, I don't see much of a problem there.
----------
Also, you probably could unburrow the zerglings somehow. One way to do it is you could send the non-hero zergling to a separate area, give it to the comp, then have something attack it. This causes the comp zergling to unburrow; then you can send it back to where it was and give it to the player.
In step by step form: (note: use normal zerglings, not devouring ones)
1) Center location on where zergling is.
2) Send zergling to another area and give it to a computer.
3) Let it be there for about 2 seconds so another computer can attack it to unburrow it.
4) Send it back to the centered location and give it back to the player.
Bam, you have a non-eud trigger. There are probably other pre-eud ways to do the same thing too!