Nice little game.
My comments on synergy would be that you've got a lot of things that give bonuses, but they aren't ever more than the bonus itself. There's nothing in your game that produces a benefit if you combine two effects; the result of everything is the sum of the two things acting together, never any more than that.
I'd also try to find a way to give the player more decisions. Currently the only thing to do is attack, and if you're not doing that the model isn't doing anything else. You've done some interesting things with the Action Points and the Spearmen, but I don't feel it's enough. Currently the game mostly will function with limited player input, and it will devolve into a lot of rolling and very little decision-making once combat starts.
You also need to work on your math. As it stands, the Elite has a 50% chance of killing the Hero outright (a 7+ on 2d6 is 50%, and in melee the R + 1 of the Hero is 4, which causes 3 damage, which kills the Hero), and the Brute's chances are far better (a 10+ on 3d6 is 50%, so a 7 is considerably better but exact numbers are out of my head atm). This is all frustrated by the fact that there's no maneuverability or decision-making on the player's part; you have to get in there to attack, and there's nothing you can really do about that. There's no mitigation at all.
Which brings me to the Noise Tokens. As written, there's no reason to use more than one character during a turn. Noise tokens will force monsters to attack that model unless there's other models in contact with them. Since the Hero is the most survivable and the most capable of killing other models, it should be the Archer (with the Handgun), until the Hero is in contact, and then the Hero should just take all actions until he's killed or you win. I guess my point is Noise is super easy to cheese.
So that's a lot but I think there's a neat little game in here if you can tighten it up. Particularly how Noise and Actions work.