For living off the land, the crops-per-harvest boost is really big.Like, it improves your food stores significant.
On the other hand, who cares about mushrooms or super-corn, given that vegetable stew takes most of the same ingredients as meat stew, and is worse, and super-corn is... definitely the best raw food, but can't be cooked into anything.
If meat was the hard part about making meat stew (as it probably should be) then vegatable stew would be a useful substitute, but you run out of potatos first, then corn, then fat, THEN meat.
Meat is far too common for vegetable stew to be appealing, and mushrooms aren't really useful for anything else.
I've got like two stacks from my small farm plot, because I never use them.
As for grease monkey, lowered vehicle costs on every level would be nice, as would fuel-efficiency.
As is, it does feel kinda wasteful to put points in, if you already have... say, the 4x4 chassis schematic.
I haven't touched Yeah science, since the whole branch feels like of wasted.
Craft-speed with every level would speed up gunpowder production significantly, which is nice, but I still feel like bandages and first-aid kits should be under the physician tree, and the mines should be under the explosives tree that governs grenades, but that would leave Science even more barran.
... I guess if we take even more things away from it, we could remove it entirely and fold all of it's perks into other stuff.
Give battery crafting to advanced engineering, alongside engine-bank crafting.
I guess Chem Station recipe could go into physician or Engineering too.
Then Yeah Science could be done away with entirely.