Units in foreign armies are usually smaller than ours; four battalions of the Iranian Army may be more like 1,200-2,000 troops.
Which, of course, is hardly "massing" of anything.
The Iranians have 2 Divisions stationed south east of Iraqi-Iranian border (One of them is Armored OR Cavalry Division). 2 Division in east of Iraqi border (Infantry). Totally 4 Divisions. And they have an Airborne group in west of Iran using AH-1 Cobras.
I don't know why they are just massing some small size battalions if they want to come in after we pull out. And why they don't use all of their power?