I know it's been tried a thousand times, but I think I have a solution for modifying Braizers to make them achieve the desired raid dynamics, small raids being easy in which the raiders just carry off some high value items but are not able to completely lay waste to a settlement.
It's simple really, rather then the Brazier hitting the Raider for Humor damage over time, the Brazier fires each time a crime is committed and it raises the humor cost of future crimes in it's area of effect exponentially. This means raiding is not a race against ongoing humor lose from simply being inside the enemy base, rather the raid becomes a more selective process of snooping/stealing/vandalizing specific high value targets before the remaining targets become too costly in humor to attack. Higher Humor characters will be able to commit more crimes, but with diminishing returns and the total crime that can be committed will not scale directly with the number of people in the raid, but rather with the surface area of the target base and how many Braizer zones are needed to cover it, each zone would be attacked up to the limit the raiders can manage before they move on to the next zone essentially giving the enemy base an even 'shave'. The Braizers effect would take a day to fade a way and it's duration is not effected by the destruction of the Brazier it's self (in fact destroying the Braizer should make the humor cost skyrocket so raiders don't do it, the idea is to keep defenses intact so raiders come back again and again for another nibble), if more then one Brazier is effecting an area then only the highest one counts.
You can still wipe out a town but that will involve siege equipment and separate mechanics like waste claims etc etc, raids are what your doing without any preparation or warning so different rules should apply to them.