https://docs.google.com/spreadsheets/d/1Cv64Vg246K8m6GoaXdL5BqYmjclufH2Q-vLjE810ISA/edit?usp=sharing
You’re welcome to inspect the numbers behind this.
In the raw data, I have color-coded blocks to make it easier to see what is happening.
In the first model, it assumes the game makes you take 4 hides at minimum level before the “average hide level” increases by 1. If you take Kurandara, you make early gains (24), but your gearing for the future is delayed, because every 5 blocks increases the hide worth by 1 point. I believe this is what you mean by “fixed ratio”. This is the worst case scenario for gearing upwards, and takes 92 battles for the higher gearing (skipping Kurandara) to become more worthwhile.
This is halfway into a Tier 4 buy, so at your Tier 6 buy you are already GUARANTEED to do better. This is just applying maths.
However, observing the points on the leaderboard for just the first hour, it quickly became clear level progression moves up much faster, so on average, the “average points” given by hides goes up by somewhere nearer to every block 3 non-mythic fights, because you can skip the lowest one until the game decides to up-level all remaining choices on the map. Doing another comparison of taking/skipping Kurandara at levels increasing every 3 blocks of fights gives us a crossover point far earlier, i.e. around 69 battles - even at Tier 2, you could possibly be better off.