This question is about broad-topic and highly cited journals such as Nature or Science in which papers submitted from different subsets of authors could cover slightly overlapping subjects.
Would a paper under review in one of these journals interfere with the submission of another paper to the same journal? Or maybe the other way around that the new submission could interfere with the editorial decisions for the paper under review? The first author would be the same in both papers but the other authors would be different and the subject of both papers would overlap slightly.
A senior colleague with extensive experience in publishing in these journals suggested that the new submission "may interfere with the paper under review" and suggested to submit to a different journal.
In theory I don't see how one submission could interfere with another given that they would have very likely different handling editors. But obviously editors communicate among each other and might think that we are "spamming" the journal. We don't submit to these journals regularly.