I've recently submitted three papers to the same top journal over a period of two weeks. Can this fact alone impact on the chances of any of the papers being accepted? There is no overlap of content or dependencies among the papers, but I'm a bit worried that it may look odd from the editor's perspective and raise doubts on my work.
I imagine this may be field and journal dependent, but in mathematics (where we have lots of journals that can be good fits for the same paper, unlike some other fields), this can reduce the chance of acceptance. Editors are under pressure to reject lots of submissions (e.g., they may have quotas), and if you have two (or more) simultaneous submissions, and the decisions are not no-brainers, many editors like accept one and reject the other(s).
Note: in mathematics, there's a tendency (not a strict rule) for people not to publish the in the same journal too often, and one of my colleagues recently got a rejection because they has "published too recently" in that journal. (I don't think it's good to enforce this practice as a rule, but apparently some people do.)
I help edit a number of journals in general medicine and health. In those journals, we would accept these submissions but would look out for salami or redundant manuscripts. I suggest that you need to address this head on in your cover letter to the editors. You need to point out in what way these two manuscripts are different. Help us reach more accurate decisions.
In addition, we have an editorial procedure that provides that we don't normally allow authors to have more than one publication appear in a single issue (the obvious exceptions being special issues, supplements or theme issues). This decision would be made, though, after successful peer review.
I agree with @kimball and disagree with the comment from @prof_santa_claus. As an associate editor of several publications and a former editor in chief of an IEEE magazine, I think 3 is at least 1 too many. And it also depends on whether this is precisely the same author(s) or just OP is intersecting.
I'd be ok if A submits with B and C and around the same time submits with D and E...especially if it's for a special issue with a single deadline. But I wouldn't take 3 from ABC around the same time regardless, I'd pick the best one or two. And I'd be really careful to be sure that indeed, the overlap is minimal.
So I do think it hurts your chances, significantly, if all the papers stood a chance independently. If one was a Hail Mary, you're just wasting your time and the reviewers, but it probably doesn't affect the others.