I mean, look. Universe level 18 is a massive outlier in terms of scaling and also it has never been implied by statements that 18 is comparable to the main U7 3-As.
In all honesty, I think a lot of characters in DBS that were, at least at one point, upgraded to 3-A never should have been.
Piccolo, 18, Trio de Dangers, Frost, etc...come to mind first but there are more especially in the ToP
They really shouldve had "At least High 4-C, likely higher" and/or "At least 4-B, likely higher" keys. I get that 3-As in DBS are way way way above baseline but most of them hadn't even defeated or stalemated a 3-A and Frost did so with poison. It's just wild to me and I'm not even a DB downplayer: I'm the guy who still wants Anilaza upgraded, Kai made canon/Toeiverse pages made, the use of SSJ multipliers to be considered legitimate, the use of guidebooks to be made legitimate, etc... these would trigger significant DB upgrades
I agree that Android 18 is almost definitely well above Large Star level+ but she doesn't have consistent 3-A feats. Maybe she's Solar System level+, maybe Galaxy level+, we don't have the feats, statements, or scaling to place her in any specific tier above High 4-C. In my head canon, she isn't High 4-C either but that can't dictate the information on the profiles