Ableton is much about fast workflow and drag&drop. But currently you can't drag an instrument oder audio to automatically create a track between two existing tracks in the arranger. Other DAWs do this (e.g. Cubase). In Ableton you have to scroll down to the last track and drop things there or you need to create an empty MIDI or audio track between two tracks and then drag & drop things there. Or am I wrong...
So drag&drop intertrack would be a helpful addition wish to get even faster.