I'm extremely new at Malifaux so I don't have much in the way of real experience, but just from reading the boards and forums and such it seems to me that many people sort of have pre-picked crews in their mind that they know/intend to use prior to starting the game, when it seems to me that the Pool of Schemes and such should be a bigger driver of crew selection/upgrades. Not every crew will be equally suited to the tasks at hand, no?
Yes. In fact this might make a good topic for an upcoming post. I think it's about the balance between using models you're proficient with vs models that are optimal for the objective.
For each master I tend to find there is a solid core of models I'll take every more of less every time and then change the rest of the crew based on the objectives and my opponent.