The devout masses rules give you D3 bone pickers and a extra normal brethren to your games gang crew. So basically it allows you two to four additional fighters on the board over your opponent. They are treated as normal fighters as well so potentially contribute to your Faith dice pool making that mechanic stronger as well.
Aside from the better movement bone pickers are the worst of any necromunda fighters, giant rays are better, but having three fairly fast fighters running around grabbing objectives while you blunderpoles phalanx are busy settings fire to folk works. They are also so cheap you can actually recoup thier cost by just running around and grabbing loot caskets.
It you are have great faith in the Emperor as your shield bone pickers make great ablative armour for your leader and champions hehe. Not only if imposed between you and the enemy do they force your opponents to target them first or pass a additional check to target you they act as a speed bump for those nasty enemy combat monsters. The Emperor will reward them! (Any luck and they could get impressive scars making them even better at it...).
Seriously just having more bodies gives you more actions over the opponent increases faith dice and makes you more resistant to Bottle tests.
You as Cawdor will have a fair few fighters in recovery every game and a fair few will be the weaker bone pickers and brethren.
Plan your gang to have say ten core members on the field ( average mission crew size) two to three good extra brethren to fill in for the two or three members of your core members in recovery from the last game to give you a steady crew of ten. Now to take advantage of the pair of Devout Masses rules, remember there are two, get two extra ordinary brethren, one to field one recovering, and Six dirt cheap bone pickers, again expecting half of them to be in recovery at any one time.
That should keep you at a crew size of 10 plus four for devout brethren in most games. And should you pick scenarios with unlimited crew size you can really horde it up with a crew potentially 20+.
