The current game configuration has impactFoliage[] = {} parameter for throwables, for now selected value for ground sound when grenade hit grass surface, trees, bushes
Game data has a excellent sounds of a grenade falling on the grass, these sounds are selected as body impact sounds in the latest dev branch update rev. 151825

This ticket requests:

1.

creation of 7 new soundImpactFoliageXYZ[] = {} values for CfgAmmo→Grenade
with A3\Sounds_F\weapons\Grenades\handgrenade_drops\handg_drop_grassdry_ paths to files

2.

changing values ​​in impactFoliage[] = {} from soundImpactSoftXYZ to new created soundImpactFoliageXYZ

from	to

See YT video comparison how it now and after actions from above https://youtu.be/CV38hvJdlT8