I’m not very far in the game yet, so this may change with the other followers, but upgrading Eveline and Toragon seems like a disadvantage: they give you the same stuff but it costs more ore. I was expecting the ore cost to drop as I upgraded them.
There is an invisible rarity drop rate increase every level.
It would be very nice to get numbers here btw…
Since the developers have decided to obscure a lot of drop data, the only numbers players have is based on observation. To get reasonably accurate estimations of these undisclosed drop rates rates you need hundreds of observations which is unrealistic for the followers at lower levels because they soon ascend to higher levels.
Actually, I mean the game should show them. There are drop rates for chests in dungeons for instance, why not adding additional ones to make the player feel some kind of improvement?
This is a helpful guide to look through / watch the video running through each of the followers and assessing their relative strengths.
Updates to the game will shift the importance or relative value of different followers when prioritising who to spend food and gold on, but you will likely quickly hit the point where it is follower crystals that become your limiting factor rather than not wanting to upgrade them higher.
As of 0.36 we just really hope something is done to increase the ore rate, as there is currently not much point having 9 followers that can craft thing using ore, but have so little ore production that you can struggle to keep 1 or 2 active.