Let's see, Harder Wildlife makes crops grow 10 times slower, if enabled. Hunger Overhaul lets you set the amount of slowdown; the default is 4 times slower. So without modifying anything I suppose they multiply each other and cause crops to grow 40 times slower? Or would one cancel out the other? Hunger Overhaul lets you set the slowdown multiplier to 1, which would mimic vanilla behavior, but again I'm left wondering if that would override Harder Wildlife's setting or not.
If it comes down to it I can disable crop slowing in Harder Wildlife and just rely on Hunger Overhaul. That would also disable Harder Wildlife's crop slowing by biome. Hunger Overhaul has a setting to make crops grow slower in the "wrong" biome, but I don't know how it decides what the wrong biome is. I can't tell how similar these features are between the two or if they would interfere with each other.
Hunger Overhaul lets you multiply vanilla's delay on how long it takes baby animals to become adults. How would that interact with Harder Wildlife's aging system?