The main reason people dislike playing against Mason's, I think. His Counter Charge, and the fact that he activates Marbles to have the same trait and so forming a double defensive bubble, makes playing into Mason's one big puzzle. That is, if you play them correctly.
The first time you play Brick, you just think he's a goalie, but he can be so much more than that. With a on 3 and having the Knockback trait, he's more than capable to keep aggressors off of your more important models. Just be sure to keep charge lanes open! When played correctly, your opponent will have to deal with Brick (and Marbles) first, or face the consequences of the charge(s). Brick, together with Marbles, is a win condition onto itself. It will require your opponent to solve the puzzle first, which will eat his clock time.
One thing to keep in mind is that the orientation of Brick and Marbles can be changed according to the situation. You can play them side by side, to defend a wider area, but this will also make it easier for the opponent to place a model in between the both of them and basically turn off their defensive bubbles. Sure, they'll have a good chance of losing that particular model, but you've just lost the protective bubble on your most important models. Most of the times, people will use speedy Mascots or 5+ models with 2" reach for this. TIP: when this happens and Brick hasn't activated yet, check the opponent's card and if there's no KD on it, just move away and thereby activate your defensive bubble again. Sure, you'll get a Parting Blow, but Brick has 2 ARM and Tough Hide. He can handle it.
You can also play them in a line, with Marbles being in front, just daring the opponent to come and get him. In this way, you increase the length of your defensive bubble, but you're more vulnerable from the sides. So be sure to think about your opponent's gameplan. Is he going to spread out? Is he trying to make a central scrum? Does he have models, which can easily turn off my bubbles?
Also, don't be scared to move the bubbles along with your front line. Hammer or Honour love having these bubbles to protect them from harm, while they themselves can project massive threat for the coming turn.
Brick's biggest problem is his movement stat of 4"/6", which can easily be affected by Character Plays because of his 2+ DEF. The Burning and Snared conditions are his greatest enemies. Playing with Brick also means that you're moving your front-line up slowly and methodically. This plays right into the gameplan of several non-interactive lists. This is mainly why I myself keep him off the Pitch against the Smoke Alchemists, Esters Brewers, Corsair Fish, the gun-line Engineers and the Hunters.
Against Tapper Brewers, Farmers, Butchers, Blacksmiths and Rage Union, he's worth his weight in gold.
Shark and Midas usually also have enough methods of keeping him occupied, although it might be a good thing to still put him on the Pitch, as it will still make goal runs somewhat of a puzzle. It's just a matter of personal choice.
Good into: scrummy teams // Risky into: speedy teams, gun-line teams
Ah, Chisel. You either love her, or downright hate her. Looking at her fluff, she's described as being this unstable murder-type player. Sure, she has Crazy and Painful Rage, but those are actually the only things going for her flavour-wise.
Looking at her Playbook, it's a damned MESS. Her is on column 4 of a total of 7 columns. Basically, to do something useful, she needs to go Crazy, have Painful Rage triggered, and her target must be Singled Out and KD'd with a 2+ or 3+ DEF. And even then, she'll be hard-pressed to do over 14 damage. If she wants to have Sadism active, that'll leave her with only 10-11 damage. With all this effort, this means that she'll now be somewhere close to the scrum. At 3+/1 and only 6-9 HP, she'll die from a stiff breeze. #NotWorth
The above statement has been the main reason why Chisel has been put into the 'non-viable' category, but this has slightly changed after @Devilsquid's post.
He talks about Chisel in a totally different way, namely as being one of his most successful ball retrievers. At 8" Sprint and 2" melee, she has a 10" threat to attack the ball with (at least) TAC 7 and having a on 2. Her Playbook is also loaded to the brim with dodges, and she can even momentously activate Feel My Pain by taking the in her third column. This will cause opposing strikers/wingers to receive 2 DMG, every time they take a swing at her. Most strikers/wingers have 10-14 HP, so this is actually quite useful. Example: attack the ball carrier, get a counter-attack, take Feel My Pain, his counter-attack hurts him, tackle the ball away, dodge around or pass the ball away. When keeping the ball, he'll most likely try and tackle it back. That's another 2 damage, and you can counter-attack and tackle, making him attack Chisel again. If you're lucky, this is 3 attacks needed to keep the ball, which causes 6 damage, along with any damage you dealt while attacking the ball, resulting in ~6-9 damage.
Just keep her away from the scrum, or speedy murder-types (Fillet, Scalpel). I myself still have to try her out in this fashion, but I'd say that you'll leave her benched against teams with ranged plays, and speedy murderers. So this means Smoke Alchemists, Brewers, Blacksmiths, Butchers, Farmers, Engineers, Hunters, Masons and Rage Union.
I think she has some merit against Fishermen, Midas Alchemists, Brisket Union and might be useful against Morticians.
Good into: footbally teams // Risky into: scrummy teams, gun-line teams, fast murderers