After reviewing a few of the legendaries on the wiki, it's come to my attention that out of all of them, Super Namekian is one of the weakest. For that, I might have come up with an idea to upgrade their abilities, and it all goes along with their tiers.
You see, unlike races such as Saiyan, Human, Ice-jin, Majin, Demon, and Alien, Nameks have no transformations at all. Androids don't have any transformations either, but the parts and chips they can buy make up for that big time. Super Namekians have some of the most basic abilities of the 9 legendary choices, making them possibly the weakest, even with the giant attacks they are able to use.
That said, for a character that happens to be a Legendary Namekian, instead of having them be a Super Namekian, then picking a tier between warrior and healer Namekian, combine the two teirs into one. Just like how Super Androids have the abilities of both Perpetual and Energy Stealing Androids, Super Namekians should be able to have both Healer, and Warrior tiers at the same time. Sure that might sound a bit Op, but it would help balance the strength and abilities of the Legendaries better. If any tweaks need to be made to balance out the abilities this upgraded Super Namekian would have, they can be discussed later on.