In Hedgewars 0.9.22, if the game modifiers “Place hogs” and “Spawn hogs at opposite sides of the terrain” are active, it seems the “Place hogs” modifier takes precedence.
The other modifier is just completely ignored here since the players can place their hedgehogs wherever they like to.

I suggest a little change:
If both these modifiers are enabled, the hogs are still placed as usual, but only at the respective side of the terrain, i.e. the first clan may only place hogs on the left side and the second clan only on the right side.

One possible use case: You could make a fort game where the hogs can be placed at start, but only on your own fort, by enabling Fort Mode, Opposite team sides and place hogs.

This special case may need some changes in the mission panel texts and also there should be a visual indication about which area is permitted. A simple colored rectangle or an effect like in Construction Mode would be more than enough, I think.