I hate to admit it, but the Strain need all the help they can get. Don't get me wrong, i'm still loving the game, but it needs a bit of tweaking. With the right mix of Vanguard units, it's pretty tough for the Strain to win, in at least campaign scenario 1 and 2. Here some modifications i've gathered from the forums which i'm going to try out in the next game:
1. Overload can only be used in active phase for Samaritans. One forum poster has been thoroughly documenting his campaign scenario 1&2 results and reports using this often in his games. This gives the Vanguard player a more balanced per-round damage output: either overload and kill a monster now, or do about the same amount of damage (possibly more) spread out in 2 attacks in active and reactive phases. Otherwise the Vanguard player will always shoot once and overload on the reactive phase to maximize damage, which is no decision at all.
Just look at him!
He needs all the help he can get!
2. Interpret the Horde +1 attack bonus to include the attacking model. Originally i interpreted this as Super Dungeon Explore's Mob effect, each additional adjacent enemy adds +1, because if you always included yourself, you might as well have added that to the base attack MOD. But really, the zombies need all the help they can get.
3. Stalker's Prowl: allow movement through blocking terrain including between section walls. Before, i restricted it to has to pass through section door area but again, they need all the help they can get.
4. Spore Engine: Reroll 1D6 until greater than 1. 'Cause a roll of 1 is just wasted action and it's boring.
5. Stalker's Homicidal Rage: According to forums, the intent was bankable max +1d6 for an attack later. And attack twice in one turn (if you don't move). This makes more sense as it keeps the stalker from being OP. However, we've been playing it as move and attack once with +1d6 or attack twice. This is a proposed rule change in the forums, but hasn't been officially adopted yet. We might keep how we're doing because it's easier to remember and to boost the Strain.
6. Movement through section doors should be straight through? I know section tiles are effectively adjacent, but according to the artwork and door placement, it seems weird you can move diagonally through 2 sets of doors at the same time on certain maps. It seems designed for straight through movement, i.e. not allowed diagonal movement around corners of the door.
7. Diagonal movement between two opponents (squeezing) or opponent and blocking terrain. I think it doesn't necessarily need to be blocked, but at least add a +1 move cost to do so. Zombies might be slow, but you still should spend effort to duck and weave to avoid their blows.