Initiative should be determined by a random factor, not by other parameters. Or are you not familiar with logic?
The downside of randomness is that it makes battles less predictable. If you want to replay a save in single-player, everything might suddenly happen differently, and the outcome might not be in your favor.
The downside of other parameters is that, yes, either you need to increase the level of nesting, or at some point, you have to revert to randomness.
But both of these are not ideal solutions. Obviously. It's clear that we want one parameter that is also deterministic, and that doesn't require using extremely large or extremely small numbers, effectively dividing all in-game situations based on initiative using a clear algorithm. And it's also clear that this is impossible; you can only have two out of three. The Era developers chose two out of three. What's wrong with that? I don't understand.