I disagree with implementing this. While it makes sense in terms of realism and evolution, I feel that it is largely unintuitive for the player to have to first evolve defensive parts… to then evolve mobility parts.
In order for progression to feel good for the player, it needs to form a path of incremental return in the desired form. So when a player wants speed, they get a little speed, and can invest to get more speed.
Other than that I am perfectly fine with incremental advancement and iterative evolution. I just don’t want players to be forced to… take a detour of sorts to get where they want.
As such my stance remains firm that baseline parts should remain independent from each other in terms of progression.