The Adapt Intent parser has the ability to handle multiple vocabulary files. It also can parse sentences to find the key words. This means that vocabulary files need only focus on keywords, not specific uterances.
For a good example of this, look at the Alarm Skill on Github: Alarm
Notice the different .voc files. For the AlarmSKillKeyword.voc file:
timer timers alarm alarms
In this example: "Set an alarm for 5 minutes from now", "Alarm 5 minutes", and "5 minute timer" all set an alarm for 5 minutes from now.
Keep this in mind when designing skills.