I agree. That was why I was asking earlier as I was puzzled and thought that it meant that defense and assault armies equally suppressed unrest. Didn't realize that it's all armies that equally suppress unrest which seems odd to me as wouldn't more powerful armies reduce unrest faster than assault and defensive armies?
I guess one goal was it to avoid the "0% happiness, no unrest" scenario.
Ever since the Supression option came along, people just dumped all unhappy pops into the Malcontent Slaves Faction. That they supressed for 2 Influence, and never had any ill effects or faction issues (the Strike from unsupressed dociles was the worst effect possible. Until they got too
much support to still do it).
Unrest effectively replaces the old Rebel Factions. With the new Factions being closer to "Political Action Comitee" and not even related to the old factions.
Unrest is a lot more granular then the old strikes. It is easier to avoid in small cases, but propably harder in extreme cases.
By putting a hard cap how much unrest supression one can stack (armies per planet + supression per army), you effectively put a cap on how far this can go.
I am willing to wager that the 0 Happiness case causes so much unrest, even with the pop/size-based army limit there will be no way to add enough unrest supression to get off free.
If they increased the supression per army, they would propably have to increase the 'size' of higher armies on the planet so you can stack less of them for the same supression. And propably rebalance the maintenance and buildng costs again.
And then there is mechanics like the Authoritarian happiness based on armies per planet called "Military Dicipline".