We're making two changes:
Unarmed Combat, Grapple (WoD, p.57)
Achieving a Grapple on a Prone target requires the attacker to also be/become Prone (WoD, pp.164-165). This will not require the extra Action of "Going Prone", as it will be part of the Grapple Action, but it will require the attacker to spend an Action to rise.
FS: Grappling, Takedown/Throw ●● (Adamantine Arrow, pp.50-51)
A successful attack will no longer automatically render the target Prone. Instead, it will have the Knockdown effect (WoD, p.168) and the target's roll will be penalized by the successes gained by the attacker.
Ex: Tracy Burns attacks Max Heinz with a Takedown, gaining 3 Successes. Max Heinz Reflexively rolls Dexterity + Athletics -3 (Tracy's Successes) to remain on his feet. Failure results in Tracy rendering Max prone.