No need for that if you have no link. Also, how did you know the other work was derived from this and not the other way around?
Oh someone else found a link proper anyways, but—besides the dates being pretty far off from each other you can tell Gyunzai does a lot of reference work from other artists and doesn't really have a style of their own. You can look at their catalogue and notice there's not really a stylistic throughline to speak for and their coloring/shading varies drastically as they bounce between reference artists. If you're familiar with them you can even spot the styles.
It's not particularly a crime in of itself; I do think it's a bit of a trait of some newer artist to mimic others down to like facial structure, eyes, etc. To pick another post for sake of example, post #7235901 has a lot of affectations of 92m's work.
