Ground fighting but not like BJJ, a possible new style of ground fighting?

There's not one single technique that could be invented that has not already been made. All you can do is rediscover old techniques. While on the ground all one really needs to do is either stand up or bring their attacker down to the ground with them. There's so little to it that it's not really even worth mentioning. There's not enough to it to even train in the situation, let alone make an entire martial art about it. If you're on the ground and they're close enough to attack you, you're close enough to take them down. Several martial arts have tactics to keep a standing opponent at bay.