The Songwriters Drumpack is MIDI performances taken from a live drummer captured via a E kit ,The Midi being the Product
Then that midi is the used to TRiGGER the SAMPLES in SD2 or EZY.
Since midi is just Note Numbers of on/off and velocity info, it can be chopped,repeated as you want and yes if you select a Drum Sound Sample that is a Brushes Hit for your snare and or toms,the same midi will then play the sound of a Brush drum(s) currently selected .

“Does songwriters pack provide more realistic sounds since the drums are played by a real drummer? “

Songwriter pack give you realistic performances played live so once you understand the whole concept the Whole answer again Yes.
Live played midi grooves Plus the Great Engine and samples in EZy combine to give you what you are wanting.