>>56058080You can view that on the individual Pokédex entries.
Victreebel has an ingredient rate of 23.30% and a helping rate of 30.86x.
Golem meanwhile has a higher ingredient rate of 27.98% but a slower helping rate of 27.87x.
Meanwhile, Gengar has a significantly low ingredient rate of 16.11% but a very fast helping rate of 39.27x
Now, the important part is how subskills and natures affect base rates.
Ingredient Finder S increases this base chance by 18%, and Ingredient Finder M raises it by 36%.
Natures increase or decrease ingredient finding rate by 20%.
The subskills stack additively and the nature multiplies that too, so the maximum increase to base ingredient finding rate is 84%.
A Victreebel can max out at 43.05% ingredient finding (+19.75%).
For a Golem, it can max out at 51.71% ingredient finding (+23.73%).
Gengar maxes out at just 29.77% ingredient finding (+13.66%).
Another factor in figuring out the quantity of ingredients gathered is how much is gathered in each slot.
Victreebel and Golem gather 5 potatoes for slot 2, but Gengar's second slot is 4 mushrooms by comparison.
In an ingredient-maxed build with no helping speed boosts, Victreebel ultimately gathers the most ingredients due to its superior helping speed and very good ingredient finding rate, whilst Gengar gathers the fewest. That's quantity however, Gengar's ingredients are fewer in number but higher in strength and is about level with Victreebel. Golem produces less ingredient strength in all due to its first slot ingredient (beans) not being that strong compared to tomatoes or herbs.
Incidentally, the maximum ingredient finding rate bonus of 84% would mean that a Pokémon with a base ingredient rate of 54.35% could theoretically achieve a 100% ingredient finding rate.
They'll probably never let that happen though.