depends what you mean by on par. Judo and bjj are sports arts. They do not teach you how to defend against getting punched, and have rules such as no throwing someone face first, grabbing the face, specific spine manipulations, leg wrapping in certain ways, eye gouge, etc.
There are a few arts that specialize on ground fighting, but also use strikes as well joint locks.
chinese arts do not believe in getting tangled in positions that restrict what you can do without being able to free yourself. At the same time, nearly all chinese arts have chin na in them, which are certain joint manipulations, as well as a few throws.
shuai chiao specializes in slamming people, but also being able to throw quickly while someone throws a punch and kick towards you.
If you want something that complements judo or bjj, I would just give you this general rule:
Nothing as a pure art is better than judo at judo, just like nothings better than boxing at boxing.
at the same time, it doesnt mean you can't take something from cma and apply it to a grappling art. I find stance training really helpful. I've had people try double and single legs on me while sparring and i just use a bow and arrow stance, 90% of the time they can't move me even when they are bigger and stronger.
You can use a lot of the chin na joint locks, and throws in various chinese arts in judo and bjj. bjj's stand up grappling in general is pretty weak, and I can see a good cma stylist going in and just throwing him around(seen it in practice).
sensitivity is also a really big thing to grappling, and if you practice push hands or search hands, you learn to feel how your opponent moves. I would actually say it's easier to apply certain things on the ground because your opponent has really restricted movement.
grappling is not really realistic for fighting imo. a lot of the times, people ask me if I want to grapple a bit, and instead of doing something like taking someone's back, i feel like it's a lot easier and more effective to just stand up and kick them in the face, or jump on them. It's a good sport if you like it though, and if you want to train for free fighting, it's probably good to at least know how your opponents fight.