The major problem with 2 assassins is the bomb is disabled...
The units aren't that great when you take away their best attribute, thats why the bomb was added in the first place.

Actually, the assassin is used for infiltration and its ability to hit multiple units. Its blocking is high enough to cause major trouble among enemy ranks. Just have to use them properly.

This formation should definitely be played aggressively, since the lack of a dmw hampers defense. However, it has a good 6-unit wall, and with the assassins' long movement range, the wall is very flexible.