Seized By works a little differently than a straight "Is everything dead?" trigger:
Seized by <side>
- Will activate when the seizing size is deemed to be in control of the area. This trigger type works with the Timeout Counter values - a low level of dominance will activate the trigger after a period of time close to the max timeout, and visa versa. Depending on unit types, the seizing side can be completely outnumbered (4:1) and still satisfy the minimum required level of presence for the Maximum timeout counter. This trigger type can also be used with the any Detected By <side> option, meaning only units known to the Detected By side will be considered by the seized by calculation. This can easily create some interesting area domination effects. For example, a Seized by BLUFOR trigger using the Detected By BLUFOR option will activate when BLUFOR think they have seized the area, while the same trigger using Detected by OPFOR option will activate when OPFOR think BLUFOR have seized the area. The Not Present option inverts the triggers normal behaviour (ie, Not Seized by <side>).