Can't the two translation groups coexist somehow?
Bc, NASS is a really big group with a lot of projects, there will be some series which have less attention compared to others. I have seen NASS's timeline, and they have posted translated chapter everyday. However, as they have many projects together, it will take time for the releasing cycle to repeat.
And for no group, as they are smaller, they have less projects but with faster speed, they could release their version first.
As long as the two have agreed in advance that there won't be any accusation in the future about bs over plagiarism then it should be ok, I think. Bc most groups afraid of such accusation that no one wants to snipe in and translate the series other groups are doing.