If I Gather/Push/otherwise move 2 Dahan at once, can I move 2 of Thunderspeaker's Presence along with them?
If I Gather/Push/otherwise move 2 Dahan at once, can I move 2 of Thunderspeaker's Presence along with them?
Yes.
The special rule says "whenever a Dahan moves ... you may move 1 Presence ...". Had you been limited to a single Presence, the rule would have been phrased, "whenever 1 or more Dahan move ... you may move 1 Presence ...".