If you want to do it in one command, you'll have to use dictation:
Set Boolean [DictationComplete] to False
Start Loop While : [DictationComplete] Equals False
Start Dictation Mode (Clearing Dictation Buffer)
Start Loop While : [{DICTATION}] Equals ''
End Loop
Stop Dictation Mode
Begin Text Compare : [{EXP: '{DICTATION}' LIKE '*roger*' Or '{DICTATION}' LIKE '*checked*' Or '{DICTATION}' LIKE '*set*'}] Equals '1'
Set Boolean [DictationComplete] to True
Else
Say, 'Please say "Roger", "Checked" or "Set"'
End Condition
End Loop
A major caveat is that this relies on the Microsoft Speech Engine's freeform dictation, rather than preset phrases like the commands, so you may find the recognition accuracy less than optimal.