My thought process of this has been that Superscalar is like a JIT, in that it attempts to optimise these instruction scheduling as it happens, always executing when viable. Bit obviously although this is good for optimising execution does come at a fairly high implementation complexity cost.

Whereas VLIW is where you optimise ahead of time with no fore knowledge, if the compiler is good enough, you get the same performance with simpler, cheaper, more efficient hardware (or potentially more performance) but often this doesn't pan out fully.