Currently it is possible to add multiple dependencies to a single trigger but in this case OR condition is used between them.

In case of host availability trigger depends on multiple routers where the connection can be routed though whichever is available then currently the host trigger is suppressed even if one of the routers is down. That is not desired because the host can be routed through other path. Ability to select AND between the dependencies would ensure that trigger is suppressed only of both routers are down.