One of the main things to always remember with malifaux is that your crew selection follows the strategies and schemes. Yes, sometimes it's not optimal to field just big models, sometimes it's great.
When you need options (if you don't want to rework the whole list) it's not hard at all to replace a 10 ss model with a pair of 5 ss necropunk objective runners, or even cheaper 4 ss watchers. Of course if you have enough damage potential, high mobility/move tricks, reactivation tricks, or the various summoning upgrades you also could not need small objective runners in your initial list. What you should take also entirely depends on the crew you're fighting against.
It's all about understanding what you're going to do and making your selections and play strategy fit the strats/schemes to get more VP than the other guy. I know that sounds self-explanatory but I think players tend to look for perfect solutions and that is a weakness in this game. In my experience there are no perfect lists in malifaux.