Glacier and Rainforest Biomes

There is a significant bump of stats required to unlock these 2 biomes compared to the other Challenging biomes (Tundra, Swamp) - this is the first time I need to wait and level up my scouts before proceeding whereas before I never had problems discovering new biomes.

Should Glacier and Rainforest be in their own category, so players are given more of a heads up on the increased difficulty?

I think this is only because almost all of our scouts are starter wolves with low stats, you will probably never encounter this problem again when you replace your lead. And it's not like you have to wait several months for it to happen.

I personally thing the category "challenging" encompasses it well enough.