I see, both those characters are a little hard to play and awkward at times. For the Noah Jumbo matchup I found using your arrows while in the air is a pretty good move, Jumbo can easily use his ground pound if you charge on the ground (unless he's otherwise occupied) and dashing into him is going to get you grabbed, I find it's best to summon and then fire some arrows, if you hit him then either use your lvl1 super arrow or rapid fire arrows to keep pressure up. Up closer your uppercut is really great, as are all your HK summons.
For Jumba, just spam orb of love, you throw it at the perfect angle to catch her in the air, it deals solid damage for a projectile, grounds her and can be followed up with a number of moves (low HK summon is great), your uppercut is also a great anti air and deals solid damage too. Generally as Noah, you also want to try and capatalize on grounded enemies as much as possible by timing arrows to hit them when they get up, even if they block it still buys you time to reposition/summon/fire more arrows. Also be wary of your wakeup uppercut, it's really great, but try to only use it if someone is right on top of you, it's easy to start spamming the buttons, whiff the wakeup attack and then get grabbed or comboed all over again.
As for Ra, I found just using his really long heavy attacks to be great against Jumbo, I've won against him like 5 times in a row just spamming HP-HK. He can't do much about it since it's too much damage to approach, it knocks back quite a bit and, he can't reposition well.
Ra does really struggle against Jumba though, I'd advise mostly using his light kick DP to try and hit her out of the air without going too high yourself, as you have zero chance of contesting her in the air, also the light unstable nebula is really great with the black hole it leaves, as it damages her and can be detonated to stop her in her tracks. Comet is also great if you need to rush in, try to avoid warping unless you need to dodge something and she's besides you, it won't let you outrun her.