You could simply order the building to train the unit(s) but this sometimes causes crashes, so you better use Unit-Create (facing angle or point). Let's see... the way of dota goes like this:
X---------------Scourge Base
l
l
l
l
l
Sentinel Base
Create a region at sentinel base, scourge base and point X. So, you create 4 ghouls (for example) at scourge base. Two triggers:
Going to point X
Events:
-A Unit enterers region Scourge Base
Conditions:
-(Entering Unit) is a Hero equal to false
-(Entering Unit) is in units owned by player 1 (red) equal to false)
Actions:
-Order (Entering Unit) to attack-move to Point X
Going to Sentinel Base
Events:
-A unit enters point X
Conditions:
-(Entering Unit) Is a hero equal to false
-(Entering Unit) is in (units owned by plauer 1 (red)) equal to false
Actions:
-Order (Entering Unit) to Attack-Move to Sentinels' Base
Or just create a region near the World Tree and order the units to attack there when they reach point X. I hope this helps. :roll:
EDIT: And obviosly do the same thing for Sentinel.
-Rui