Unit Group Limitations?

Are there limitations for the number of units that can be in a unit group via the Unit Group - Add Unit action? Right now I've got this map, and since I can't program, I've got a bunch of triggers set up to simulate a computer opponent's AI. Like this:

Event: Every 30 seconds of game time
Action: Order Barracks X to train/upgrade to a Grunt

Event: A unit owned by (Player) finishes training a unit
Condition: Unit-type of Trained unit is equal to Grunt
Action: Add trained unit to "AttackGroup"

Event: A unit owned by (Player) finishes training a unit
Condition: (Player) food used greater than or equal to 80
Action: Unit Group - Order AttackGroup to Attack/Move To (random point in Attack 1)

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That last one is a simplified version of the actual attack trigger... I've got it set up so that the attack command is issued, then all production halts for 3 minutes before it begins anew (thus giving the computer time to lose some units). Seems like this should work flawlessly. However, after the first attack, the computer has been sending only 1 unit with the attack. Why is this?

Are there limitations to the number of units allowed in a unit group -- or limitations to the number of units the computer will issue orders to at one time?

Thanks,
GS

Well, heh.. to answer my own question... I guess that "yes," there is a unit limitation in unit groups. It seems to be 12 -- same as the number of units you can select at one time in-game. I suppose they're the same thing, eh?

Well, to get around my problem, I created a separate train/group/attack trigger set for each unit type, and now it works like a charm.

Glad to hear it ^.^