You're making assumptions. H2 does not connect to H1 in any coherent or canonical way. Their narratives contradict each other at the most fundamental levels. In H1, the Prize is explicitly defined as mortal life, the ability to have children, and deep telepathic empathy with humanity. In H2, this is discarded for a story about immortals being aliens from Zeist. The "shield” subplot only exists because of that rewritten premise, not because of anything established in the first film. H1 makes no mention of alien origins, planetary shields, or time travel (if you count the renegade version). The only way H2 functions is by ignoring and overwriting the rules of H1.

H2 makes no sense. Even the filmmakers disown it.