If active model C declares a Discover + Attack against reactive model A and shoots a weapon with an impact template (e.g. light rocket launcher). When is the template placed and when does reactive model B, who will be under the template, react? Is it when the attack is declared? (In this example active model C is not in ZoC of reactive models A or B).
Templates are always placed on declaration. Anyone under the template will be able to declare a Dodge (-3 if no LoF) on top of any other ARO they'd have valid.
Probably worth noting that it does depend a little on if B is in C's ZoC. That would generate an ARO during the Discover declaration. If they chose not to declare one at that point the opportunity to ARO would be lost. That would make it in their best interest to look at C's profile (provided it isn't private of course) and decide if they want to Dodge or Reset.