If there are multiple "if I conquer" effects happening at once, do I have to place all of them on the chain at once? Or can I put them on multiple chains?

According to Rule 330.1, "Only one Chain can exist at a time." Therefore, you cannot place triggered abilities on multiple chains.

When multiple "When I conquer" (Conquer) effects trigger simultaneously, they all go on the same chain. According to Rule 383.3.d, you (the controller of the abilities) choose the order in which they are placed on that chain.

As outlined in RiftJudge FAQ #7665:

  • All "When I conquer" triggers go on the chain in your chosen order.
  • The chain resolves one item at a time (Last-In, First-Out).
  • You can order them as you please, and they will wait on the chain to resolve even if other effects (such as triggers from cards played during the resolution of the first effect) are added and resolve in between.

In summary: You must place all simultaneous triggers on the same chain, and you determine the order in which they are placed.