Another idea I'm thinking could be to make Fusilade operate as a hybrid between Lance Formation, and the Screamer slash attack...
Declare a unit you wish to fusilade against during the charge phase. You must move full speed at it, but may move through the unit. When you do, all your front-rank and flank pistoliers (think Lance Formation) may perform their shooting attacks against the unit. Units may elect to flee but can be caught/destroyed as normal...if they escape, the pistoliers move foward as a failed charge...
Pistoliers can attempt to fusilade multiple units in a row, provided they're all on a straight line and they can move their full 16".
Of course, I would probably like to see Pistoliers as core still but that seems to have people angry...