I'm searching for the fastest way to make a unit disappear without deleting it.
On a units TUnitAuSol main page, just below the parameter MaxDeployableAmount is a list that says something like 'IsVisibleInMenu' (I can't remember the exact name off the topo of my head)
Open up that list, select the first 'True' value, uncheck the box so it becomes 'False'
The unit will now vanish from the armory.
If you do this to units that are first in a series in the armory (they're linked by the IsUnitUpgrade parameter in TUniteAuSol) then all the subsequent units will be hidden as well.
Thanks! I'll do this instead from now on.