One example how he get standards is when he is attacking Edo Minato, ninja or clone summon by Orochimaru GNW is the same.

Edo Minato passive is whoever attack him, the attacker will receive ignition and tag if not mistaken.(His passive works even if Edo Minato dodge)

Ignition is a debuff, so as long Edo Minato is not gone from field, Pain or Shisui who have the (Get multiple standard attacks when receiving debuff) can get their full cap standards in a round when attacking Edo Minato.