No, Myrkul, Lord of Bones‘s second capability is a triggered capability, not a alternative capability. When Solemn Simulacrum dies, it triggers each its personal capability and Myrkul’s capability on the identical time. You get to decide on the order that they go on the stack, but it surely doesn’t matter on this case, you’ll each draw a card and exile Simulacrum.

Word that the flexibility begins with “when”. All skills that begin with “when” are triggered skills.

603.1. Triggered skills have a set off situation and an impact. They’re written as “[When/Whenever/At] [trigger condition or event], [effect]. [Instructions (if any).]”